diff --git a/adev/package.json b/adev/package.json
index ceb86b0d7f5..aa0afb580d3 100644
--- a/adev/package.json
+++ b/adev/package.json
@@ -64,7 +64,7 @@
     "character-entities-legacy": "^3.0.0",
     "comma-separated-tokens": "^2.0.3",
     "crelt": "1.0.6",
-    "diff": "8.0.4",
+    "diff": "9.0.0",
     "emoji-regex": "10.6.0",
     "fflate": "0.8.2",
     "hast-util-to-html": "^9.0.5",
diff --git a/adev/shared-docs/package.json b/adev/shared-docs/package.json
index 2d55c00b8dd..eb7cd12f9cb 100644
--- a/adev/shared-docs/package.json
+++ b/adev/shared-docs/package.json
@@ -15,7 +15,7 @@
   },
   "dependencies": {
     "@webcontainer/api": "^1.1.8",
-    "diff": "~8.0.0",
+    "diff": "~9.0.0",
     "emoji-regex": "~10.6.0",
     "fflate": "^0.8.2",
     "jsdom": "~29.0.0",
diff --git a/package.json b/package.json
index 28309fecd5d..929357c9c67 100644
--- a/package.json
+++ b/package.json
@@ -118,7 +118,7 @@
     "convert-source-map": "^1.5.1",
     "d3": "^7.0.0",
     "dagre-d3-es": "^7.0.14",
-    "diff": "^8.0.0",
+    "diff": "^9.0.0",
     "domino": "https://github.com/angular/domino.git#928dffb9d9431b2cd2a73d7b940d1575f221e072",
     "esbuild": "0.28.0",
     "esbuild-plugin-umd-wrapper": "^3.0.0",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 5cf49a0b359..a3babd84731 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -206,8 +206,8 @@ importers:
         specifier: ^7.0.14
         version: 7.0.14
       diff:
-        specifier: ^8.0.0
-        version: 8.0.4
+        specifier: ^9.0.0
+        version: 9.0.0
       domino:
         specifier: https://github.com/angular/domino.git#928dffb9d9431b2cd2a73d7b940d1575f221e072
         version: '@angular/domino@https://codeload.github.com/angular/domino/tar.gz/928dffb9d9431b2cd2a73d7b940d1575f221e072'
@@ -645,8 +645,8 @@ importers:
         specifier: 1.0.6
         version: 1.0.6
       diff:
-        specifier: 8.0.4
-        version: 8.0.4
+        specifier: 9.0.0
+        version: 9.0.0
       emoji-regex:
         specifier: 10.6.0
         version: 10.6.0
@@ -772,8 +772,8 @@ importers:
         specifier: ^1.1.8
         version: 1.6.1
       diff:
-        specifier: ~8.0.0
-        version: 8.0.4
+        specifier: ~9.0.0
+        version: 9.0.0
       emoji-regex:
         specifier: ~10.6.0
         version: 10.6.0
@@ -7812,6 +7812,10 @@ packages:
     resolution: {integrity: sha512-DPi0FmjiSU5EvQV0++GFDOJ9ASQUVFh5kD+OzOnYdi7n3Wpm9hWWGfB/O2blfHcMVTL5WkQXSnRiK9makhrcnw==}
     engines: {node: '>=0.3.1'}
 
+  diff@9.0.0:
+    resolution: {integrity: sha512-svtcdpS8CgJyqAjEQIXdb3OjhFVVYjzGAPO8WGCmRbrml64SPw/jJD4GoE98aR7r25A0XcgrK3F02yw9R/vhQw==}
+    engines: {node: '>=0.3.1'}
+
   discontinuous-range@1.0.0:
     resolution: {integrity: sha512-c68LpLbO+7kP/b1Hr1qs8/BJ09F5khZGTxqxZuhzxpmwJKOgRFHJWIb9/KmqnqHhLdO55aOxFH/EGBvUQbL/RQ==}
 
@@ -21123,6 +21127,8 @@ snapshots:
 
   diff@8.0.4: {}
 
+  diff@9.0.0: {}
+
   discontinuous-range@1.0.0: {}
 
   dlv@1.1.3: {}