diff --git a/.jules/sentinel.md b/.jules/sentinel.md
new file mode 100644
index 0000000..5644c81
--- /dev/null
+++ b/.jules/sentinel.md
@@ -0,0 +1,4 @@
+## 2024-05-18 - [Predictable Temporary File Vulnerability]
+**Vulnerability:** Predictable temporary file path `/tmp/yq` used in `tools/os_installers/apt.sh` to download and install `yq` as root.
+**Learning:** Hardcoding a predictable file path in the world-writable directory `/tmp` could allow an attacker to launch a symlink attack or pre-create the file to gain privilege escalation when the script later runs `sudo mv /tmp/yq /usr/local/bin/yq`. This is especially dangerous in setup scripts that may be run by different users or multiple times.
+**Prevention:** Always use `mktemp` (e.g., `mktemp -d`) to create secure, unpredictable temporary directories or files when downloading artifacts or storing intermediate data, especially if they are going to be accessed by `sudo` later.
\ No newline at end of file
diff --git a/tools/os_installers/apt.sh b/tools/os_installers/apt.sh
index 156016b..15e9bfc 100644
--- a/tools/os_installers/apt.sh
+++ b/tools/os_installers/apt.sh
@@ -231,9 +231,11 @@ fi
 echo "Installing yq..."
 if ! command -v yq &> /dev/null; then
     YQ_VERSION="v4.44.6"
-    wget "https://github.com/mikefarah/yq/releases/download/${YQ_VERSION}/yq_linux_amd64" -O /tmp/yq
-    sudo mv /tmp/yq /usr/local/bin/yq
+    TMP_DIR="$(mktemp -d)"
+    wget "https://github.com/mikefarah/yq/releases/download/${YQ_VERSION}/yq_linux_amd64" -O "$TMP_DIR/yq"
+    sudo mv "$TMP_DIR/yq" /usr/local/bin/yq
     sudo chmod +x /usr/local/bin/yq
+    rm -rf "$TMP_DIR"
 fi
 
 # Install lsd (LSDeluxe)