diff --git a/packages/discord.js/package.json b/packages/discord.js/package.json
index 413d13815160..5d9d8813deb1 100644
--- a/packages/discord.js/package.json
+++ b/packages/discord.js/package.json
@@ -78,7 +78,7 @@
     "lodash.snakecase": "4.1.1",
     "magic-bytes.js": "^1.10.0",
     "tslib": "^2.6.3",
-    "undici": "6.21.1"
+    "undici": "6.21.3"
   },
   "devDependencies": {
     "@discordjs/api-extractor": "workspace:^",
diff --git a/packages/rest/package.json b/packages/rest/package.json
index 66d387aca242..f0ef2d918818 100644
--- a/packages/rest/package.json
+++ b/packages/rest/package.json
@@ -91,7 +91,7 @@
 		"discord-api-types": "^0.38.1",
 		"magic-bytes.js": "^1.10.0",
 		"tslib": "^2.6.3",
-		"undici": "6.21.1"
+		"undici": "6.21.3"
 	},
 	"devDependencies": {
 		"@discordjs/api-extractor": "workspace:^",
diff --git a/packages/ws/package.json b/packages/ws/package.json
index 6b2974627426..bbfe0502ec0a 100644
--- a/packages/ws/package.json
+++ b/packages/ws/package.json
@@ -100,7 +100,7 @@
 		"tsup": "^8.2.4",
 		"turbo": "^2.0.14",
 		"typescript": "~5.5.4",
-		"undici": "6.21.1",
+		"undici": "6.21.3",
 		"vitest": "^2.0.5",
 		"zlib-sync": "^0.1.10"
 	},
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 2ca1037f15bb..9a96855c629d 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -968,8 +968,8 @@ importers:
         specifier: ^2.6.3
         version: 2.6.3
       undici:
-        specifier: 6.21.1
-        version: 6.21.1
+        specifier: 6.21.3
+        version: 6.21.3
     devDependencies:
       '@discordjs/api-extractor':
         specifier: workspace:^
@@ -1331,8 +1331,8 @@ importers:
         specifier: ^2.6.3
         version: 2.6.3
       undici:
-        specifier: 6.21.1
-        version: 6.21.1
+        specifier: 6.21.3
+        version: 6.21.3
     devDependencies:
       '@discordjs/api-extractor':
         specifier: workspace:^
@@ -1774,8 +1774,8 @@ importers:
         specifier: ~5.5.4
         version: 5.5.4
       undici:
-        specifier: 6.21.1
-        version: 6.21.1
+        specifier: 6.21.3
+        version: 6.21.3
       vitest:
         specifier: ^2.0.5
         version: 2.0.5(@edge-runtime/vm@3.2.0)(@types/node@18.19.45)(happy-dom@14.12.3)(terser@5.39.0)
@@ -13977,6 +13977,10 @@ packages:
     resolution: {integrity: sha512-q/1rj5D0/zayJB2FraXdaWxbhWiNKDvu8naDT2dl1yTlvJp4BLtOcp2a5BvgGNQpYYJzau7tf1WgKv3b+7mqpQ==}
     engines: {node: '>=18.17'}
 
+  undici@6.21.3:
+    resolution: {integrity: sha512-gBLkYIlEnSp8pFbT64yFgGE6UIB9tAkhukC23PmMDCe5Nd+cRqKxSjw5y54MK2AZMgZfJWMaNE4nYUHgi1XEOw==}
+    engines: {node: '>=18.17'}
+
   undici@7.8.0:
     resolution: {integrity: sha512-vFv1GA99b7eKO1HG/4RPu2Is3FBTWBrmzqzO0mz+rLxN3yXkE4mqRcb8g8fHxzX4blEysrNZLqg5RbJLqX5buA==}
     engines: {node: '>=20.18.1'}
@@ -31404,6 +31408,8 @@ snapshots:
 
   undici@6.21.1: {}
 
+  undici@6.21.3: {}
+
   undici@7.8.0: {}
 
   unicode-canonical-property-names-ecmascript@2.0.0: {}