diff --git a/dd-java-agent/instrumentation-testing/src/main/groovy/datadog/trace/agent/test/base/HttpServerTest.groovy b/dd-java-agent/instrumentation-testing/src/main/groovy/datadog/trace/agent/test/base/HttpServerTest.groovy
index 0b2a28d954b..a599a987cbc 100644
--- a/dd-java-agent/instrumentation-testing/src/main/groovy/datadog/trace/agent/test/base/HttpServerTest.groovy
+++ b/dd-java-agent/instrumentation-testing/src/main/groovy/datadog/trace/agent/test/base/HttpServerTest.groovy
@@ -65,6 +65,8 @@ import java.util.function.Supplier
 
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.BODY_JSON
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.BODY_MULTIPART
+import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.BODY_MULTIPART_COMBINED
+import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.BODY_MULTIPART_REPEATED
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.BODY_URLENCODED
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.CREATED
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.CREATED_IS
@@ -368,6 +370,14 @@ abstract class HttpServerTest<SERVER> extends WithHttpServer<SERVER> {
     false
   }
 
+  boolean testBodyFilenamesCalledOnce() {
+    false
+  }
+
+  boolean testBodyFilenamesCalledOnceCombined() {
+    false
+  }
+
   boolean testBodyFilenames() {
     false
   }
@@ -476,6 +486,8 @@ abstract class HttpServerTest<SERVER> extends WithHttpServer<SERVER> {
     CREATED_IS("created_input_stream", 201, "created"),
     BODY_URLENCODED("body-urlencoded?ignore=pair", 200, '[a:[x]]'),
     BODY_MULTIPART("body-multipart?ignore=pair", 200, '[a:[x]]'),
+    BODY_MULTIPART_REPEATED("body-multipart-repeated", 200, "ok"),
+    BODY_MULTIPART_COMBINED("body-multipart-combined", 200, "ok"),
     BODY_JSON("body-json", 200, '{"a":"x"}'),
     BODY_XML("body-xml", 200, '<foo attr="attr_value">mytext<bar/></foo>'),
     REDIRECT("redirect", 302, "/redirected"),
@@ -1646,6 +1658,54 @@ abstract class HttpServerTest<SERVER> extends WithHttpServer<SERVER> {
     response.close()
   }
 
+  def 'test instrumentation gateway file upload filenames called once'() {
+    setup:
+    assumeTrue(testBodyFilenamesCalledOnce())
+    RequestBody fileBody = RequestBody.create(MediaType.parse('application/octet-stream'), 'file content')
+    def body = new MultipartBody.Builder()
+    .setType(MultipartBody.FORM)
+    .addFormDataPart('file', 'evil.php', fileBody)
+    .build()
+    def httpRequest = request(BODY_MULTIPART_REPEATED, 'POST', body).build()
+    def response = client.newCall(httpRequest).execute()
+
+    when:
+    TEST_WRITER.waitForTraces(1)
+
+    then:
+    TEST_WRITER.get(0).any {
+      it.getTag('request.body.filenames') == "[evil.php]"
+      && it.getTag('_dd.appsec.filenames.cb.calls') == 1
+    }
+
+    cleanup:
+    response.close()
+  }
+
+  def 'test instrumentation gateway file upload filenames called once via parameter map'() {
+    setup:
+    assumeTrue(testBodyFilenamesCalledOnceCombined())
+    RequestBody fileBody = RequestBody.create(MediaType.parse('application/octet-stream'), 'file content')
+    def body = new MultipartBody.Builder()
+    .setType(MultipartBody.FORM)
+    .addFormDataPart('file', 'evil.php', fileBody)
+    .build()
+    def httpRequest = request(BODY_MULTIPART_COMBINED, 'POST', body).build()
+    def response = client.newCall(httpRequest).execute()
+
+    when:
+    TEST_WRITER.waitForTraces(1)
+
+    then:
+    TEST_WRITER.get(0).any {
+      it.getTag('request.body.filenames') == "[evil.php]"
+      && it.getTag('_dd.appsec.filenames.cb.calls') == 1
+    }
+
+    cleanup:
+    response.close()
+  }
+
   def 'test instrumentation gateway json request body'() {
     setup:
     assumeTrue(testBodyJson())
@@ -2581,6 +2641,7 @@ abstract class HttpServerTest<SERVER> extends WithHttpServer<SERVER> {
       boolean responseBodyTag
       Object responseBody
       List<String> uploadedFilenames
+      int uploadedFilenamesCallCount = 0
     }
 
     static final String stringOrEmpty(String string) {
@@ -2754,6 +2815,8 @@ abstract class HttpServerTest<SERVER> extends WithHttpServer<SERVER> {
       rqCtxt.traceSegment.setTagTop('request.body.filenames', filenames as String)
       Context context = rqCtxt.getData(RequestContextSlot.APPSEC)
       context.uploadedFilenames = filenames
+      context.uploadedFilenamesCallCount++
+      rqCtxt.traceSegment.setTagTop('_dd.appsec.filenames.cb.calls', context.uploadedFilenamesCallCount)
       Flow.ResultFlow.empty()
     } as BiFunction<RequestContext, List<String>, Flow<Void>>)
 
diff --git a/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-8.1.3/src/main/java/datadog/trace/instrumentation/jetty8/MultipartHelper.java b/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-8.1.3/src/main/java/datadog/trace/instrumentation/jetty8/MultipartHelper.java
new file mode 100644
index 00000000000..28426fd9667
--- /dev/null
+++ b/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-8.1.3/src/main/java/datadog/trace/instrumentation/jetty8/MultipartHelper.java
@@ -0,0 +1,38 @@
+package datadog.trace.instrumentation.jetty8;
+
+public class MultipartHelper {
+
+  private MultipartHelper() {}
+
+  /**
+   * Extracts the filename value from a {@code Content-Disposition} header string.
+   *
+   * <p>Jetty 8 implements Servlet 3.0, where {@code Part.getSubmittedFileName()} does not exist.
+   * This method parses the filename from the header manually.
+   *
+   * <p>Examples of handled inputs:
+   *
+   * <pre>
+   *   form-data; name="file"; filename="photo.jpg"  → "photo.jpg"
+   *   form-data; name="file"; filename=photo.jpg    → "photo.jpg"
+   * </pre>
+   *
+   * @return the filename, or {@code null} if not present or empty
+   */
+  public static String filenameFromContentDisposition(String cd) {
+    if (cd == null) {
+      return null;
+    }
+    for (String tok : cd.split(";")) {
+      tok = tok.trim();
+      if (tok.startsWith("filename=")) {
+        String name = tok.substring(9).trim();
+        if (name.startsWith("\"") && name.endsWith("\"")) {
+          name = name.substring(1, name.length() - 1);
+        }
+        return name.isEmpty() ? null : name;
+      }
+    }
+    return null;
+  }
+}
diff --git a/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-8.1.3/src/main/java/datadog/trace/instrumentation/jetty8/RequestGetPartsInstrumentation.java b/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-8.1.3/src/main/java/datadog/trace/instrumentation/jetty8/RequestGetPartsInstrumentation.java
index 104a3affa7c..515f988e5bd 100644
--- a/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-8.1.3/src/main/java/datadog/trace/instrumentation/jetty8/RequestGetPartsInstrumentation.java
+++ b/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-8.1.3/src/main/java/datadog/trace/instrumentation/jetty8/RequestGetPartsInstrumentation.java
@@ -7,6 +7,8 @@
 
 import com.google.auto.service.AutoService;
 import datadog.appsec.api.blocking.BlockingException;
+import datadog.trace.advice.ActiveRequestContext;
+import datadog.trace.advice.RequiresRequestContext;
 import datadog.trace.agent.tooling.Instrumenter;
 import datadog.trace.agent.tooling.InstrumenterModule;
 import datadog.trace.api.gateway.BlockResponseFunction;
@@ -18,8 +20,12 @@
 import datadog.trace.bootstrap.instrumentation.api.AgentTracer;
 import java.io.IOException;
 import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
 import java.util.function.BiFunction;
 import javax.servlet.ServletException;
+import javax.servlet.http.Part;
 import net.bytebuddy.asm.Advice;
 import net.bytebuddy.asm.AsmVisitorWrapper;
 import net.bytebuddy.description.field.FieldDescription;
@@ -27,6 +33,7 @@
 import net.bytebuddy.description.method.MethodList;
 import net.bytebuddy.description.type.TypeDescription;
 import net.bytebuddy.implementation.Implementation;
+import net.bytebuddy.implementation.bytecode.assign.Assigner;
 import net.bytebuddy.jar.asm.ClassReader;
 import net.bytebuddy.jar.asm.ClassVisitor;
 import net.bytebuddy.jar.asm.ClassWriter;
@@ -58,6 +65,7 @@ public String[] helperClassNames() {
       packageName + ".ParameterCollector",
       packageName + ".ParameterCollector$ParameterCollectorImpl",
       packageName + ".ParameterCollector$ParameterCollectorNoop",
+      packageName + ".MultipartHelper",
     };
   }
 
@@ -74,6 +82,8 @@ public void methodAdvice(MethodTransformer transformer) {
             .and(takesArgument(0, String.class))
             .or(named("getParts").and(takesArguments(0))),
         getClass().getName() + "$GetPartsAdvice");
+    transformer.applyAdvice(
+        named("getParts").and(takesArguments(0)), getClass().getName() + "$GetFilenamesAdvice");
   }
 
   @Override
@@ -194,6 +204,60 @@ static void muzzle(Request req) throws ServletException, IOException {
     }
   }
 
+  @RequiresRequestContext(RequestContextSlot.APPSEC)
+  public static class GetFilenamesAdvice {
+    @Advice.OnMethodEnter(suppress = Throwable.class)
+    static boolean before(
+        @Advice.FieldValue(value = "_multiPartInputStream", typing = Assigner.Typing.DYNAMIC)
+            final Object multiPartInputStream) {
+      // _multiPartInputStream is null only on the first getParts() call; subsequent calls
+      // return the cached multipart result without re-parsing, but we must not re-fire the WAF.
+      return multiPartInputStream == null;
+    }
+
+    @Advice.OnMethodExit(suppress = Throwable.class, onThrowable = Throwable.class)
+    static void after(
+        @Advice.Enter boolean proceed,
+        @Advice.Return Collection<Part> parts,
+        @ActiveRequestContext RequestContext reqCtx,
+        @Advice.Thrown(readOnly = false) Throwable t) {
+      if (!proceed || t != null || parts == null || parts.isEmpty()) {
+        return;
+      }
+      // Jetty 8 implements Servlet 3.0; getSubmittedFileName does not exist.
+      // Parse filename from Content-Disposition header instead.
+      List<String> filenames = new ArrayList<>();
+      for (Part part : parts) {
+        String name =
+            MultipartHelper.filenameFromContentDisposition(part.getHeader("content-disposition"));
+        if (name != null) {
+          filenames.add(name);
+        }
+      }
+      if (filenames.isEmpty()) {
+        return;
+      }
+      CallbackProvider cbp = AgentTracer.get().getCallbackProvider(RequestContextSlot.APPSEC);
+      BiFunction<RequestContext, List<String>, Flow<Void>> callback =
+          cbp.getCallback(EVENTS.requestFilesFilenames());
+      if (callback == null) {
+        return;
+      }
+      Flow<Void> flow = callback.apply(reqCtx, filenames);
+      Flow.Action action = flow.getAction();
+      if (action instanceof Flow.Action.RequestBlockingAction) {
+        Flow.Action.RequestBlockingAction rba = (Flow.Action.RequestBlockingAction) action;
+        BlockResponseFunction brf = reqCtx.getBlockResponseFunction();
+        if (brf != null) {
+          brf.tryCommitBlockingResponse(reqCtx.getTraceSegment(), rba);
+          if (t == null) {
+            t = new BlockingException("Blocked request (multipart file upload)");
+          }
+        }
+      }
+    }
+  }
+
   public static class GetPartsVisitorWrapper implements AsmVisitorWrapper {
     @Override
     public int mergeWriter(int flags) {
diff --git a/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-8.1.3/src/test/groovy/datadog/trace/instrumentation/jetty8/MultipartHelperTest.groovy b/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-8.1.3/src/test/groovy/datadog/trace/instrumentation/jetty8/MultipartHelperTest.groovy
new file mode 100644
index 00000000000..46d96465146
--- /dev/null
+++ b/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-8.1.3/src/test/groovy/datadog/trace/instrumentation/jetty8/MultipartHelperTest.groovy
@@ -0,0 +1,28 @@
+package datadog.trace.instrumentation.jetty8
+
+import spock.lang.Specification
+import spock.lang.Unroll
+
+class MultipartHelperTest extends Specification {
+
+  @Unroll
+  def "filenameFromContentDisposition: #description"() {
+    expect:
+    MultipartHelper.filenameFromContentDisposition(cd) == expected
+
+    where:
+    description                          | cd                                                        | expected
+    'null input'                         | null                                                      | null
+    'no filename token'                  | 'form-data; name="upload"'                                | null
+    'quoted filename'                    | 'form-data; name="upload"; filename="photo.jpg"'          | 'photo.jpg'
+    'unquoted filename'                  | 'form-data; name="upload"; filename=photo.jpg'            | 'photo.jpg'
+    'filename with spaces'               | 'form-data; filename="my file.jpg"'                       | 'my file.jpg'
+    'empty quoted filename'              | 'form-data; name="f"; filename=""'                        | null
+    'empty unquoted filename'            | 'form-data; name="f"; filename='                          | null
+    'whitespace-only unquoted filename'  | 'form-data; name="f"; filename=  '                        | null
+    'filename first token'               | 'filename="evil.php"'                                     | 'evil.php'
+    'extra spaces around semicolons'     | 'form-data ;  name="f" ;  filename="a.txt" '              | 'a.txt'
+    'filename with dots and dashes'      | 'form-data; filename="my-file.v2.tar.gz"'                 | 'my-file.v2.tar.gz'
+    'stops at first filename= token'     | 'form-data; filename="first.jpg"; filename="second.jpg"'  | 'first.jpg'
+  }
+}
diff --git a/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-9.2/src/main/java/datadog/trace/instrumentation/jetty92/MultipartHelper.java b/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-9.2/src/main/java/datadog/trace/instrumentation/jetty92/MultipartHelper.java
new file mode 100644
index 00000000000..714a6bd5339
--- /dev/null
+++ b/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-9.2/src/main/java/datadog/trace/instrumentation/jetty92/MultipartHelper.java
@@ -0,0 +1,32 @@
+package datadog.trace.instrumentation.jetty92;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import javax.servlet.http.Part;
+
+public class MultipartHelper {
+
+  private MultipartHelper() {}
+
+  /**
+   * Extracts non-null, non-empty filenames from a collection of multipart {@link Part}s using
+   * {@link Part#getSubmittedFileName()} (Servlet 3.1+).
+   *
+   * @return list of filenames; never {@code null}, may be empty
+   */
+  public static List<String> extractFilenames(Collection<Part> parts) {
+    if (parts == null || parts.isEmpty()) {
+      return Collections.emptyList();
+    }
+    List<String> filenames = new ArrayList<>();
+    for (Part part : parts) {
+      String name = part.getSubmittedFileName();
+      if (name != null && !name.isEmpty()) {
+        filenames.add(name);
+      }
+    }
+    return filenames;
+  }
+}
diff --git a/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-9.2/src/main/java/datadog/trace/instrumentation/jetty92/RequestExtractContentParametersInstrumentation.java b/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-9.2/src/main/java/datadog/trace/instrumentation/jetty92/RequestExtractContentParametersInstrumentation.java
index 0796aa32538..f43bfd88143 100644
--- a/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-9.2/src/main/java/datadog/trace/instrumentation/jetty92/RequestExtractContentParametersInstrumentation.java
+++ b/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-9.2/src/main/java/datadog/trace/instrumentation/jetty92/RequestExtractContentParametersInstrumentation.java
@@ -19,7 +19,10 @@
 import datadog.trace.api.gateway.RequestContextSlot;
 import datadog.trace.bootstrap.CallDepthThreadLocalMap;
 import datadog.trace.bootstrap.instrumentation.api.AgentTracer;
+import java.util.Collection;
+import java.util.List;
 import java.util.function.BiFunction;
+import javax.servlet.http.Part;
 import net.bytebuddy.asm.Advice;
 import org.eclipse.jetty.server.Request;
 import org.eclipse.jetty.util.MultiMap;
@@ -38,6 +41,11 @@ public String instrumentedType() {
     return "org.eclipse.jetty.server.Request";
   }
 
+  @Override
+  public String[] helperClassNames() {
+    return new String[] {packageName + ".MultipartHelper"};
+  }
+
   @Override
   public void methodAdvice(MethodTransformer transformer) {
     transformer.applyAdvice(
@@ -48,6 +56,7 @@ public void methodAdvice(MethodTransformer transformer) {
             .and(takesArguments(1))
             .and(takesArgument(0, named("org.eclipse.jetty.util.MultiMap"))),
         getClass().getName() + "$GetPartsAdvice");
+    transformer.applyAdvice(named("getParts"), getClass().getName() + "$GetFilenamesAdvice");
   }
 
   private static final Reference REQUEST_REFERENCE =
@@ -135,4 +144,48 @@ static void after(
       }
     }
   }
+
+  @RequiresRequestContext(RequestContextSlot.APPSEC)
+  public static class GetFilenamesAdvice {
+    @Advice.OnMethodEnter(suppress = Throwable.class)
+    static boolean before(@Advice.FieldValue("_contentParameters") final MultiMap<String> map) {
+      final int callDepth = CallDepthThreadLocalMap.incrementCallDepth(Collection.class);
+      return callDepth == 0 && map == null;
+    }
+
+    @Advice.OnMethodExit(suppress = Throwable.class, onThrowable = Throwable.class)
+    static void after(
+        @Advice.Enter boolean proceed,
+        @Advice.Return Collection<Part> parts,
+        @ActiveRequestContext RequestContext reqCtx,
+        @Advice.Thrown(readOnly = false) Throwable t) {
+      CallDepthThreadLocalMap.decrementCallDepth(Collection.class);
+      if (!proceed || t != null || parts == null || parts.isEmpty()) {
+        return;
+      }
+      List<String> filenames = MultipartHelper.extractFilenames(parts);
+      if (filenames.isEmpty()) {
+        return;
+      }
+      CallbackProvider cbp = AgentTracer.get().getCallbackProvider(RequestContextSlot.APPSEC);
+      BiFunction<RequestContext, List<String>, Flow<Void>> callback =
+          cbp.getCallback(EVENTS.requestFilesFilenames());
+      if (callback == null) {
+        return;
+      }
+      Flow<Void> flow = callback.apply(reqCtx, filenames);
+      Flow.Action action = flow.getAction();
+      if (action instanceof Flow.Action.RequestBlockingAction) {
+        Flow.Action.RequestBlockingAction rba = (Flow.Action.RequestBlockingAction) action;
+        BlockResponseFunction brf = reqCtx.getBlockResponseFunction();
+        if (brf != null) {
+          brf.tryCommitBlockingResponse(reqCtx.getTraceSegment(), rba);
+          if (t == null) {
+            t = new BlockingException("Blocked request (multipart file upload)");
+            reqCtx.getTraceSegment().effectivelyBlocked();
+          }
+        }
+      }
+    }
+  }
 }
diff --git a/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-9.2/src/test/groovy/datadog/trace/instrumentation/jetty92/MultipartHelperTest.groovy b/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-9.2/src/test/groovy/datadog/trace/instrumentation/jetty92/MultipartHelperTest.groovy
new file mode 100644
index 00000000000..51bdb50c564
--- /dev/null
+++ b/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-9.2/src/test/groovy/datadog/trace/instrumentation/jetty92/MultipartHelperTest.groovy
@@ -0,0 +1,71 @@
+package datadog.trace.instrumentation.jetty92
+
+import javax.servlet.http.Part
+import spock.lang.Specification
+
+class MultipartHelperTest extends Specification {
+
+  def "returns empty list for null collection"() {
+    expect:
+    MultipartHelper.extractFilenames(null) == []
+  }
+
+  def "returns empty list for empty collection"() {
+    expect:
+    MultipartHelper.extractFilenames([]) == []
+  }
+
+  def "returns empty list when all parts have null filename"() {
+    given:
+    def parts = [part(null), part(null)]
+
+    expect:
+    MultipartHelper.extractFilenames(parts) == []
+  }
+
+  def "returns empty list when all parts have empty filename"() {
+    given:
+    def parts = [part(''), part('')]
+
+    expect:
+    MultipartHelper.extractFilenames(parts) == []
+  }
+
+  def "extracts filename from single part"() {
+    given:
+    def parts = [part('photo.jpg')]
+
+    expect:
+    MultipartHelper.extractFilenames(parts) == ['photo.jpg']
+  }
+
+  def "extracts filenames from multiple parts"() {
+    given:
+    def parts = [part('a.jpg'), part('b.png'), part('c.pdf')]
+
+    expect:
+    MultipartHelper.extractFilenames(parts) == ['a.jpg', 'b.png', 'c.pdf']
+  }
+
+  def "skips parts with null or empty filename and keeps valid ones"() {
+    given:
+    def parts = [part(null), part('valid.txt'), part(''), part('other.zip')]
+
+    expect:
+    MultipartHelper.extractFilenames(parts) == ['valid.txt', 'other.zip']
+  }
+
+  def "preserves filenames with spaces and special characters"() {
+    given:
+    def parts = [part('my file.tar.gz'), part('résumé.pdf')]
+
+    expect:
+    MultipartHelper.extractFilenames(parts) == ['my file.tar.gz', 'résumé.pdf']
+  }
+
+  private Part part(String submittedFileName) {
+    Part p = Stub(Part)
+    p.getSubmittedFileName() >> submittedFileName
+    return p
+  }
+}
diff --git a/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-9.3/src/main/java/datadog/trace/instrumentation/jetty93/RequestExtractContentParametersInstrumentation.java b/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-9.3/src/main/java/datadog/trace/instrumentation/jetty93/RequestExtractContentParametersInstrumentation.java
index 3e1e2bf6d5c..a102c1e9981 100644
--- a/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-9.3/src/main/java/datadog/trace/instrumentation/jetty93/RequestExtractContentParametersInstrumentation.java
+++ b/dd-java-agent/instrumentation/jetty/jetty-appsec/jetty-appsec-9.3/src/main/java/datadog/trace/instrumentation/jetty93/RequestExtractContentParametersInstrumentation.java
@@ -18,6 +18,10 @@
 import datadog.trace.api.gateway.RequestContextSlot;
 import datadog.trace.bootstrap.CallDepthThreadLocalMap;
 import datadog.trace.bootstrap.instrumentation.api.AgentTracer;
+import java.lang.reflect.Method;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
 import java.util.function.BiFunction;
 import net.bytebuddy.asm.Advice;
 import org.eclipse.jetty.server.Request;
@@ -42,6 +46,11 @@ public void methodAdvice(MethodTransformer transformer) {
     transformer.applyAdvice(
         named("extractContentParameters").and(takesArguments(0)).or(named("getParts")),
         getClass().getName() + "$ExtractContentParametersAdvice");
+    transformer.applyAdvice(
+        named("getParts").and(takesArguments(0)), getClass().getName() + "$GetFilenamesAdvice");
+    transformer.applyAdvice(
+        named("getParts").and(takesArguments(1)),
+        getClass().getName() + "$GetFilenamesFromMultiPartAdvice");
   }
 
   private static final Reference REQUEST_REFERENCE =
@@ -99,4 +108,172 @@ static void after(
       }
     }
   }
+
+  /**
+   * Fires the {@code requestFilesFilenames} event when the application calls public {@code
+   * getParts()}. Guards prevent double-firing:
+   *
+   * <ul>
+   *   <li>{@code contentParameters != null}: set by {@code extractContentParameters()} (the {@code
+   *       getParameterMap()} path); means filenames were already reported via {@code
+   *       GetFilenamesFromMultiPartAdvice}.
+   *   <li>{@code _multiParts != null} (Jetty 9.4+, read via reflection): set by the first {@code
+   *       getParts()} call; means filenames were already reported. In Jetty 9.3 this field does not
+   *       exist, so the reflection throws {@code NoSuchFieldException} and we treat it as null.
+   * </ul>
+   */
+  @RequiresRequestContext(RequestContextSlot.APPSEC)
+  public static class GetFilenamesAdvice {
+    @Advice.OnMethodEnter(suppress = Throwable.class)
+    static boolean before(
+        @Advice.FieldValue("_contentParameters") final MultiMap<String> contentParameters,
+        @Advice.This final Request request) {
+      final int callDepth = CallDepthThreadLocalMap.incrementCallDepth(Collection.class);
+      if (callDepth != 0 || contentParameters != null) {
+        return false;
+      }
+      // Check the multipart cache field to detect repeated calls.
+      // Jetty 9.4+: _multiParts is set after the first getParts() call.
+      // Jetty 9.3.x: _multiPartInputStream is set instead (_multiParts doesn't exist).
+      // A non-null value means getParts() was already invoked and filenames were reported.
+      try {
+        java.lang.reflect.Field f = request.getClass().getDeclaredField("_multiParts");
+        f.setAccessible(true);
+        if (f.get(request) != null) {
+          return false;
+        }
+      } catch (NoSuchFieldException e9_3) {
+        try {
+          java.lang.reflect.Field f = request.getClass().getDeclaredField("_multiPartInputStream");
+          f.setAccessible(true);
+          if (f.get(request) != null) {
+            return false;
+          }
+        } catch (Exception ignored) {
+        }
+      } catch (Exception ignored) {
+      }
+      return true;
+    }
+
+    @Advice.OnMethodExit(suppress = Throwable.class, onThrowable = Throwable.class)
+    static void after(
+        @Advice.Enter boolean proceed,
+        @Advice.Return Collection parts,
+        @ActiveRequestContext RequestContext reqCtx,
+        @Advice.Thrown(readOnly = false) Throwable t) {
+      CallDepthThreadLocalMap.decrementCallDepth(Collection.class);
+      if (!proceed || t != null || parts == null || parts.isEmpty()) {
+        return;
+      }
+      Method getSubmittedFileName = null;
+      try {
+        getSubmittedFileName = parts.iterator().next().getClass().getMethod("getSubmittedFileName");
+      } catch (Exception ignored) {
+      }
+      if (getSubmittedFileName == null) {
+        return;
+      }
+      List<String> filenames = new ArrayList<>();
+      for (Object part : parts) {
+        try {
+          String name = (String) getSubmittedFileName.invoke(part);
+          if (name != null && !name.isEmpty()) {
+            filenames.add(name);
+          }
+        } catch (Exception ignored) {
+        }
+      }
+      if (filenames.isEmpty()) {
+        return;
+      }
+      CallbackProvider cbp = AgentTracer.get().getCallbackProvider(RequestContextSlot.APPSEC);
+      BiFunction<RequestContext, List<String>, Flow<Void>> callback =
+          cbp.getCallback(EVENTS.requestFilesFilenames());
+      if (callback == null) {
+        return;
+      }
+      Flow<Void> flow = callback.apply(reqCtx, filenames);
+      Flow.Action action = flow.getAction();
+      if (action instanceof Flow.Action.RequestBlockingAction) {
+        Flow.Action.RequestBlockingAction rba = (Flow.Action.RequestBlockingAction) action;
+        BlockResponseFunction brf = reqCtx.getBlockResponseFunction();
+        if (brf != null) {
+          brf.tryCommitBlockingResponse(reqCtx.getTraceSegment(), rba);
+          if (t == null) {
+            t = new BlockingException("Blocked request (multipart file upload)");
+            reqCtx.getTraceSegment().effectivelyBlocked();
+          }
+        }
+      }
+    }
+  }
+
+  /**
+   * Fires the {@code requestFilesFilenames} event when multipart content is parsed via the internal
+   * {@code getParts(MultiMap)} path triggered by {@code getParameter*()} / {@code
+   * getParameterMap()} — i.e. when the application never calls public {@code getParts()}. In Jetty
+   * 9.3+, {@code extractContentParameters()} assigns {@code _contentParameters} before calling this
+   * method, so {@code map == null} cannot be used as a "first parse" guard here; the call-depth
+   * guard prevents double-firing when {@code getParts()} internally delegates to this method.
+   */
+  @RequiresRequestContext(RequestContextSlot.APPSEC)
+  public static class GetFilenamesFromMultiPartAdvice {
+    @Advice.OnMethodEnter(suppress = Throwable.class)
+    static boolean before() {
+      return CallDepthThreadLocalMap.incrementCallDepth(Collection.class) == 0;
+    }
+
+    @Advice.OnMethodExit(suppress = Throwable.class, onThrowable = Throwable.class)
+    static void after(
+        @Advice.Enter boolean proceed,
+        @Advice.Return Collection parts,
+        @ActiveRequestContext RequestContext reqCtx,
+        @Advice.Thrown(readOnly = false) Throwable t) {
+      CallDepthThreadLocalMap.decrementCallDepth(Collection.class);
+      if (!proceed || t != null || parts == null || parts.isEmpty()) {
+        return;
+      }
+      Method getSubmittedFileName = null;
+      try {
+        getSubmittedFileName = parts.iterator().next().getClass().getMethod("getSubmittedFileName");
+      } catch (Exception ignored) {
+      }
+      if (getSubmittedFileName == null) {
+        return;
+      }
+      List<String> filenames = new ArrayList<>();
+      for (Object part : parts) {
+        try {
+          String name = (String) getSubmittedFileName.invoke(part);
+          if (name != null && !name.isEmpty()) {
+            filenames.add(name);
+          }
+        } catch (Exception ignored) {
+        }
+      }
+      if (filenames.isEmpty()) {
+        return;
+      }
+      CallbackProvider cbp = AgentTracer.get().getCallbackProvider(RequestContextSlot.APPSEC);
+      BiFunction<RequestContext, List<String>, Flow<Void>> callback =
+          cbp.getCallback(EVENTS.requestFilesFilenames());
+      if (callback == null) {
+        return;
+      }
+      Flow<Void> flow = callback.apply(reqCtx, filenames);
+      Flow.Action action = flow.getAction();
+      if (action instanceof Flow.Action.RequestBlockingAction) {
+        Flow.Action.RequestBlockingAction rba = (Flow.Action.RequestBlockingAction) action;
+        BlockResponseFunction brf = reqCtx.getBlockResponseFunction();
+        if (brf != null) {
+          brf.tryCommitBlockingResponse(reqCtx.getTraceSegment(), rba);
+          if (t == null) {
+            t = new BlockingException("Blocked request (multipart file upload)");
+            reqCtx.getTraceSegment().effectivelyBlocked();
+          }
+        }
+      }
+    }
+  }
 }
diff --git a/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-10.0/src/test/groovy/datadog/trace/instrumentation/jetty10/Jetty10Test.groovy b/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-10.0/src/test/groovy/datadog/trace/instrumentation/jetty10/Jetty10Test.groovy
index 7dec61c223f..2726574ec83 100644
--- a/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-10.0/src/test/groovy/datadog/trace/instrumentation/jetty10/Jetty10Test.groovy
+++ b/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-10.0/src/test/groovy/datadog/trace/instrumentation/jetty10/Jetty10Test.groovy
@@ -85,6 +85,21 @@ abstract class Jetty10Test extends HttpServerTest<Server> {
     true
   }
 
+  @Override
+  boolean testBodyFilenames() {
+    true
+  }
+
+  @Override
+  boolean testBodyFilenamesCalledOnce() {
+    true
+  }
+
+  @Override
+  boolean testBodyFilenamesCalledOnceCombined() {
+    true
+  }
+
   @Override
   boolean testSessionId() {
     true
diff --git a/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-11.0/src/test/groovy/Jetty11Test.groovy b/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-11.0/src/test/groovy/Jetty11Test.groovy
index f4da48aaaf3..80afb31077a 100644
--- a/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-11.0/src/test/groovy/Jetty11Test.groovy
+++ b/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-11.0/src/test/groovy/Jetty11Test.groovy
@@ -67,6 +67,21 @@ abstract class Jetty11Test extends HttpServerTest<Server> {
     true
   }
 
+  @Override
+  boolean testBodyFilenames() {
+    true
+  }
+
+  @Override
+  boolean testBodyFilenamesCalledOnce() {
+    true
+  }
+
+  @Override
+  boolean testBodyFilenamesCalledOnceCombined() {
+    true
+  }
+
   @Override
   boolean testBlocking() {
     true
diff --git a/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-11.0/src/test/groovy/JettyAsyncHandlerTest.groovy b/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-11.0/src/test/groovy/JettyAsyncHandlerTest.groovy
index 38f5b1449ab..bd1e1bb9ecc 100644
--- a/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-11.0/src/test/groovy/JettyAsyncHandlerTest.groovy
+++ b/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-11.0/src/test/groovy/JettyAsyncHandlerTest.groovy
@@ -25,6 +25,11 @@ class JettyAsyncHandlerTest extends Jetty11Test implements TestingGenericHttpNam
     false
   }
 
+  @Override
+  boolean testBodyFilenames() {
+    false
+  }
+
   static class ContinuationTestHandler implements Handler {
     @Delegate
     private final Handler delegate
diff --git a/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-9.0.4/src/test/groovy/datadog/trace/instrumentation/jetty9/Jetty9Test.groovy b/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-9.0.4/src/test/groovy/datadog/trace/instrumentation/jetty9/Jetty9Test.groovy
index 38eb20340c6..8a18ccbc652 100644
--- a/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-9.0.4/src/test/groovy/datadog/trace/instrumentation/jetty9/Jetty9Test.groovy
+++ b/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-9.0.4/src/test/groovy/datadog/trace/instrumentation/jetty9/Jetty9Test.groovy
@@ -85,6 +85,21 @@ abstract class Jetty9Test extends HttpServerTest<Server> {
     true
   }
 
+  @Override
+  boolean testBodyFilenames() {
+    true
+  }
+
+  @Override
+  boolean testBodyFilenamesCalledOnce() {
+    true
+  }
+
+  @Override
+  boolean testBodyFilenamesCalledOnceCombined() {
+    true
+  }
+
   @Override
   boolean testSessionId() {
     true
diff --git a/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-9.0/src/test/groovy/datadog/trace/instrumentation/jetty9/Jetty9Test.groovy b/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-9.0/src/test/groovy/datadog/trace/instrumentation/jetty9/Jetty9Test.groovy
index 32a1b300c28..9bdc9e1e469 100644
--- a/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-9.0/src/test/groovy/datadog/trace/instrumentation/jetty9/Jetty9Test.groovy
+++ b/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-9.0/src/test/groovy/datadog/trace/instrumentation/jetty9/Jetty9Test.groovy
@@ -84,6 +84,21 @@ abstract class Jetty9Test extends HttpServerTest<Server> {
     true
   }
 
+  @Override
+  boolean testBodyFilenames() {
+    true
+  }
+
+  @Override
+  boolean testBodyFilenamesCalledOnce() {
+    true
+  }
+
+  @Override
+  boolean testBodyFilenamesCalledOnceCombined() {
+    true
+  }
+
   @Override
   boolean testSessionId() {
     true
diff --git a/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-9.3/src/test/groovy/datadog/trace/instrumentation/jetty9/Jetty9Test.groovy b/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-9.3/src/test/groovy/datadog/trace/instrumentation/jetty9/Jetty9Test.groovy
index 32a1b300c28..9bdc9e1e469 100644
--- a/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-9.3/src/test/groovy/datadog/trace/instrumentation/jetty9/Jetty9Test.groovy
+++ b/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-9.3/src/test/groovy/datadog/trace/instrumentation/jetty9/Jetty9Test.groovy
@@ -84,6 +84,21 @@ abstract class Jetty9Test extends HttpServerTest<Server> {
     true
   }
 
+  @Override
+  boolean testBodyFilenames() {
+    true
+  }
+
+  @Override
+  boolean testBodyFilenamesCalledOnce() {
+    true
+  }
+
+  @Override
+  boolean testBodyFilenamesCalledOnceCombined() {
+    true
+  }
+
   @Override
   boolean testSessionId() {
     true
diff --git a/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-9.4.21/src/test/groovy/datadog/trace/instrumentation/jetty9/Jetty9Test.groovy b/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-9.4.21/src/test/groovy/datadog/trace/instrumentation/jetty9/Jetty9Test.groovy
index 38eb20340c6..8a18ccbc652 100644
--- a/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-9.4.21/src/test/groovy/datadog/trace/instrumentation/jetty9/Jetty9Test.groovy
+++ b/dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-9.4.21/src/test/groovy/datadog/trace/instrumentation/jetty9/Jetty9Test.groovy
@@ -85,6 +85,21 @@ abstract class Jetty9Test extends HttpServerTest<Server> {
     true
   }
 
+  @Override
+  boolean testBodyFilenames() {
+    true
+  }
+
+  @Override
+  boolean testBodyFilenamesCalledOnce() {
+    true
+  }
+
+  @Override
+  boolean testBodyFilenamesCalledOnceCombined() {
+    true
+  }
+
   @Override
   boolean testSessionId() {
     true
diff --git a/dd-java-agent/instrumentation/servlet/jakarta-servlet-5.0/src/testFixtures/groovy/datadog/trace/instrumentation/servlet5/TestServlet5.groovy b/dd-java-agent/instrumentation/servlet/jakarta-servlet-5.0/src/testFixtures/groovy/datadog/trace/instrumentation/servlet5/TestServlet5.groovy
index 51e7c974f6d..93060644456 100644
--- a/dd-java-agent/instrumentation/servlet/jakarta-servlet-5.0/src/testFixtures/groovy/datadog/trace/instrumentation/servlet5/TestServlet5.groovy
+++ b/dd-java-agent/instrumentation/servlet/jakarta-servlet-5.0/src/testFixtures/groovy/datadog/trace/instrumentation/servlet5/TestServlet5.groovy
@@ -11,6 +11,8 @@ import java.lang.reflect.Field
 import java.lang.reflect.Modifier
 
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.BODY_MULTIPART
+import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.BODY_MULTIPART_COMBINED
+import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.BODY_MULTIPART_REPEATED
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.BODY_URLENCODED
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.CREATED
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.CREATED_IS
@@ -68,6 +70,22 @@ class TestServlet5 extends HttpServlet {
           resp.status = endpoint.status
           resp.writer.print(req.getHeader("x-forwarded-for"))
           break
+        case BODY_MULTIPART_REPEATED:
+          resp.status = endpoint.status
+        // Call getParts() 3 times to verify the filenames callback fires only once
+          req.getParts()
+          req.getParts()
+          req.getParts()
+          resp.writer.print(endpoint.body)
+          break
+        case BODY_MULTIPART_COMBINED:
+          resp.status = endpoint.status
+        // Call getParameterMap() first (exercises GetFilenamesFromMultiPartAdvice via extractContentParameters),
+        // then getParts() explicitly (GetFilenamesAdvice must not double-fire since map is already set)
+          req.parameterMap
+          req.getParts()
+          resp.writer.print(endpoint.body)
+          break
         case BODY_MULTIPART:
         case BODY_URLENCODED:
           resp.status = endpoint.status
diff --git a/dd-java-agent/instrumentation/servlet/javax-servlet/javax-servlet-3.0/src/testFixtures/groovy/datadog/trace/instrumentation/servlet3/TestServlet3.groovy b/dd-java-agent/instrumentation/servlet/javax-servlet/javax-servlet-3.0/src/testFixtures/groovy/datadog/trace/instrumentation/servlet3/TestServlet3.groovy
index 4b0b9df85d4..98a5983a36d 100644
--- a/dd-java-agent/instrumentation/servlet/javax-servlet/javax-servlet-3.0/src/testFixtures/groovy/datadog/trace/instrumentation/servlet3/TestServlet3.groovy
+++ b/dd-java-agent/instrumentation/servlet/javax-servlet/javax-servlet-3.0/src/testFixtures/groovy/datadog/trace/instrumentation/servlet3/TestServlet3.groovy
@@ -15,6 +15,8 @@ import java.lang.reflect.Modifier
 
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.BODY_URLENCODED
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.BODY_MULTIPART
+import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.BODY_MULTIPART_COMBINED
+import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.BODY_MULTIPART_REPEATED
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.CREATED
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.CREATED_IS
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.CUSTOM_EXCEPTION
@@ -95,6 +97,22 @@ class TestServlet3 {
             resp.status = endpoint.status
             resp.writer.print(endpoint.bodyForQuery(req.queryString))
             break
+          case BODY_MULTIPART_REPEATED:
+            resp.status = endpoint.status
+          // Call getParts() 3 times to verify the filenames callback fires only once
+            req.getParts()
+            req.getParts()
+            req.getParts()
+            resp.writer.print(endpoint.body)
+            break
+          case BODY_MULTIPART_COMBINED:
+            resp.status = endpoint.status
+          // Call getParameterMap() first (exercises GetFilenamesFromMultiPartAdvice via extractContentParameters),
+          // then getParts() explicitly (GetFilenamesAdvice must not double-fire since map is already set)
+            req.parameterMap
+            req.getParts()
+            resp.writer.print(endpoint.body)
+            break
           case BODY_URLENCODED:
           case BODY_MULTIPART:
             resp.status = endpoint.status