diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3bc70a0..8c0fd78 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - [#68](https://github.com/itk-dev/devops_itksites/pull/68)
   6667: Update advisories on Detailed site display
 
+- [#68](https://github.com/itk-dev/devops_itksites/pull/68)
+  6667: Show sites affected on advisories.
+
 ## [1.9.2] - 2026-04-07
 
 - [#67](https://github.com/itk-dev/devops_itksites/pull/67)
diff --git a/src/Admin/Field/AffectedSitesField.php b/src/Admin/Field/AffectedSitesField.php
new file mode 100644
index 0000000..058b5b6
--- /dev/null
+++ b/src/Admin/Field/AffectedSitesField.php
@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Admin\Field;
+
+use EasyCorp\Bundle\EasyAdminBundle\Contracts\Field\FieldInterface;
+use EasyCorp\Bundle\EasyAdminBundle\Field\FieldTrait;
+use Symfony\Contracts\Translation\TranslatableInterface;
+
+class AffectedSitesField implements FieldInterface
+{
+    use FieldTrait;
+
+    public static function new(string $propertyName, TranslatableInterface|string|bool|null $label = null): self
+    {
+        return new self()
+            ->setProperty($propertyName)
+            ->setLabel($label)
+            ->setTemplatePath('EasyAdminBundle/Fields/affected_sites.html.twig');
+    }
+}
diff --git a/src/Controller/Admin/AdvisoryCrudController.php b/src/Controller/Admin/AdvisoryCrudController.php
index 8e89d9b..50c18ec 100644
--- a/src/Controller/Admin/AdvisoryCrudController.php
+++ b/src/Controller/Admin/AdvisoryCrudController.php
@@ -4,6 +4,7 @@
 
 namespace App\Controller\Admin;
 
+use App\Admin\Field\AffectedSitesField;
 use App\Admin\Field\SourcesField;
 use App\Admin\Field\TextMonospaceField;
 use App\Entity\Advisory;
@@ -58,6 +59,7 @@ public function configureFields(string $pageName): iterable
         yield DateField::new('reportedAt')->setColumns(6)->onlyOnIndex();
         yield DateTimeField::new('reportedAt')->setColumns(6)->onlyOnDetail();
         yield SourcesField::new('sourceLinks')->setColumns(6)->onlyOnDetail();
+        yield AffectedSitesField::new('sites')->setLabel('Affected Sites');
     }
 
     #[\Override]
diff --git a/src/Entity/Advisory.php b/src/Entity/Advisory.php
index 160a914..586f15e 100644
--- a/src/Entity/Advisory.php
+++ b/src/Entity/Advisory.php
@@ -190,6 +190,23 @@ public function removePackageVersion(PackageVersion $packageVersion): self
         return $this;
     }
 
+    /**
+     * @return Collection<int, Site>
+     */
+    public function getSites(): Collection
+    {
+        $sites = [];
+        foreach ($this->packageVersions as $packageVersion) {
+            foreach ($packageVersion->getInstallations() as $installation) {
+                foreach ($installation->getSites() as $site) {
+                    $sites[$site->getId()->toRfc4122()] = $site;
+                }
+            }
+        }
+
+        return new ArrayCollection(array_values($sites));
+    }
+
     public function getPackage(): ?Package
     {
         return $this->package;
diff --git a/templates/EasyAdminBundle/Fields/affected_sites.html.twig b/templates/EasyAdminBundle/Fields/affected_sites.html.twig
new file mode 100644
index 0000000..a2eb5e3
--- /dev/null
+++ b/templates/EasyAdminBundle/Fields/affected_sites.html.twig
@@ -0,0 +1,33 @@
+{# @var ea \EasyCorp\Bundle\EasyAdminBundle\Context\AdminContext #}
+{# @var field \EasyCorp\Bundle\EasyAdminBundle\Dto\FieldDto #}
+{# @var entity \EasyCorp\Bundle\EasyAdminBundle\Dto\EntityDto #}
+{% set sites = entity.instance.sites %}
+{% if ea().crud.currentAction == 'detail' %}
+    {% if sites|length > 0 %}
+        <table class="table table-sm table-borderless">
+            <thead>
+                <tr>
+                    <th>Domain</th>
+                    <th>Server</th>
+                </tr>
+            </thead>
+            <tbody>
+                {% for site in sites %}
+                    {% set url = ea_url()
+                        .unsetAll()
+                        .setController('App\\Controller\\Admin\\SiteCrudController')
+                        .setAction('detail')
+                        .setEntityId(site.id) %}
+                    <tr>
+                        <td><a href="{{ url }}">{{ site.primaryDomain }}</a></td>
+                        <td>{{ site.server }}</td>
+                    </tr>
+                {% endfor %}
+            </tbody>
+        </table>
+    {% else %}
+        <span class="text-muted">None</span>
+    {% endif %}
+{% else %}
+    <span class="badge badge-info">{{ sites|length }}</span>
+{% endif %}