diff --git a/extensions/copilot/package-lock.json b/extensions/copilot/package-lock.json
index df5570d9811512..9c35c714993ad3 100644
--- a/extensions/copilot/package-lock.json
+++ b/extensions/copilot/package-lock.json
@@ -43,7 +43,7 @@
 				"applicationinsights": "^2.9.7",
 				"best-effort-json-parser": "^1.2.1",
 				"diff": "^8.0.3",
-				"dompurify": "^3.4.1",
+				"dompurify": "^3.4.9",
 				"express": "^5.2.1",
 				"ignore": "^7.0.5",
 				"isbinaryfile": "^5.0.4",
@@ -9478,9 +9478,9 @@
 			}
 		},
 		"node_modules/dompurify": {
-			"version": "3.4.1",
-			"resolved": "https://registry.npmjs.org/dompurify/-/dompurify-3.4.1.tgz",
-			"integrity": "sha512-JahakDAIg1gyOm7dlgWSDjV4n7Ip2PKR55NIT6jrMfIgLFgWo81vdr1/QGqWtFNRqXP9UV71oVePtjqS2ebnPw==",
+			"version": "3.4.9",
+			"resolved": "https://registry.npmjs.org/dompurify/-/dompurify-3.4.9.tgz",
+			"integrity": "sha512-4dPSRMRDqHvs0V4YDFCsaIZo4if5u0xM+llyxiM2fwuZFdKArUBAF3VtI2+n8NKg9P870WMdYk0UhqQNoWXbfQ==",
 			"license": "(MPL-2.0 OR Apache-2.0)",
 			"optionalDependencies": {
 				"@types/trusted-types": "^2.0.7"
diff --git a/extensions/copilot/package.json b/extensions/copilot/package.json
index a12de99ce35eb1..4faa015a296765 100644
--- a/extensions/copilot/package.json
+++ b/extensions/copilot/package.json
@@ -6738,7 +6738,7 @@
 		"applicationinsights": "^2.9.7",
 		"best-effort-json-parser": "^1.2.1",
 		"diff": "^8.0.3",
-		"dompurify": "^3.4.1",
+		"dompurify": "^3.4.9",
 		"express": "^5.2.1",
 		"ignore": "^7.0.5",
 		"isbinaryfile": "^5.0.4",