diff --git a/CHANGELOG.md b/CHANGELOG.md
index cdbc4a5a87..7cfb4c2ebf 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,7 +6,7 @@ Note that the only difference between `v2` and `v3` of the CodeQL Action is the
 
 ## [UNRELEASED]
 
-No user facing changes.
+- Update default CodeQL bundle version to 2.19.4. [#2621](https://github.com/github/codeql-action/pull/2621)
 
 ## 3.27.4 - 14 Nov 2024
 
diff --git a/lib/defaults.json b/lib/defaults.json
index 71daeec20c..2e084a4ce5 100644
--- a/lib/defaults.json
+++ b/lib/defaults.json
@@ -1,6 +1,6 @@
 {
-    "bundleVersion": "codeql-bundle-v2.19.3",
-    "cliVersion": "2.19.3",
-    "priorBundleVersion": "codeql-bundle-v2.19.2",
-    "priorCliVersion": "2.19.2"
+    "bundleVersion": "codeql-bundle-v2.19.4",
+    "cliVersion": "2.19.4",
+    "priorBundleVersion": "codeql-bundle-v2.19.3",
+    "priorCliVersion": "2.19.3"
 }
diff --git a/src/defaults.json b/src/defaults.json
index 7ee20851fa..6e0e0dbbce 100644
--- a/src/defaults.json
+++ b/src/defaults.json
@@ -1,6 +1,6 @@
 {
-  "bundleVersion": "codeql-bundle-v2.19.3",
-  "cliVersion": "2.19.3",
-  "priorBundleVersion": "codeql-bundle-v2.19.2",
-  "priorCliVersion": "2.19.2"
+  "bundleVersion": "codeql-bundle-v2.19.4",
+  "cliVersion": "2.19.4",
+  "priorBundleVersion": "codeql-bundle-v2.19.3",
+  "priorCliVersion": "2.19.3"
 }