diff --git a/CHANGELOG.md b/CHANGELOG.md
index 48d6a4b5e..a5da78c2d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Upgraded `protobufjs` to `^7.6.2`. [#1281](https://github.com/sourcebot-dev/sourcebot/pull/1281)
 - Upgraded `picomatch` to `^4.0.4`. [#1283](https://github.com/sourcebot-dev/sourcebot/pull/1283)
 - Fixed GitLab MR inline review comments returning 400 Bad Request on context (unchanged) lines and renamed files. [#1149](https://github.com/sourcebot-dev/sourcebot/pull/1149)
+- Upgraded `ws` to `^8.20.1`. [#1286](https://github.com/sourcebot-dev/sourcebot/pull/1286)
 
 ## [5.0.1] - 2026-06-04
 
diff --git a/yarn.lock b/yarn.lock
index c3be599c5..9dd4dfb98 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -10333,6 +10333,15 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@types/ws@npm:^8.5.12":
+  version: 8.18.1
+  resolution: "@types/ws@npm:8.18.1"
+  dependencies:
+    "@types/node": "npm:*"
+  checksum: 10c0/61aff1129143fcc4312f083bc9e9e168aa3026b7dd6e70796276dcfb2c8211c4292603f9c4864fae702f2ed86e4abd4d38aa421831c2fd7f856c931a481afbab
+  languageName: node
+  linkType: hard
+
 "@typescript-eslint/eslint-plugin@npm:8.56.1":
   version: 8.56.1
   resolution: "@typescript-eslint/eslint-plugin@npm:8.56.1"
@@ -12854,7 +12863,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"debug@npm:~4.3.1, debug@npm:~4.3.2, debug@npm:~4.3.4":
+"debug@npm:~4.3.2":
   version: 4.3.7
   resolution: "debug@npm:4.3.7"
   dependencies:
@@ -13359,19 +13368,20 @@ __metadata:
   linkType: hard
 
 "engine.io@npm:~6.6.0":
-  version: 6.6.4
-  resolution: "engine.io@npm:6.6.4"
+  version: 6.6.8
+  resolution: "engine.io@npm:6.6.8"
   dependencies:
     "@types/cors": "npm:^2.8.12"
     "@types/node": "npm:>=10.0.0"
+    "@types/ws": "npm:^8.5.12"
     accepts: "npm:~1.3.4"
     base64id: "npm:2.0.0"
     cookie: "npm:~0.7.2"
     cors: "npm:~2.8.5"
-    debug: "npm:~4.3.1"
+    debug: "npm:~4.4.1"
     engine.io-parser: "npm:~5.2.1"
-    ws: "npm:~8.17.1"
-  checksum: 10c0/845761163f8ea7962c049df653b75dafb6b3693ad6f59809d4474751d7b0392cbf3dc2730b8a902ff93677a91fd28711d34ab29efd348a8a4b49c6b0724021ab
+    ws: "npm:~8.20.1"
+  checksum: 10c0/3cf705d4be8683322b3ff3c09e680ca72e03f2a475b2c76e5945c920aa85b6edc4ef442df18b0a1a7eaa205797802b993ed9f194bff27ed09f46b43711e88af2
   languageName: node
   linkType: hard
 
@@ -21313,12 +21323,12 @@ __metadata:
   linkType: hard
 
 "socket.io-adapter@npm:~2.5.2":
-  version: 2.5.5
-  resolution: "socket.io-adapter@npm:2.5.5"
+  version: 2.5.7
+  resolution: "socket.io-adapter@npm:2.5.7"
   dependencies:
-    debug: "npm:~4.3.4"
-    ws: "npm:~8.17.1"
-  checksum: 10c0/04a5a2a9c4399d1b6597c2afc4492ab1e73430cc124ab02b09e948eabf341180b3866e2b61b5084cb899beb68a4db7c328c29bda5efb9207671b5cb0bc6de44e
+    debug: "npm:~4.4.1"
+    ws: "npm:~8.20.1"
+  checksum: 10c0/c911e18e2a8a1cf30117d3df7f6309a6d1c802cc3cc1115606d75e0928ea270978800725d4557526bfb1853ccaa2bc33b0d221a361cd2653bdd00b7e313ffab0
   languageName: node
   linkType: hard
 
@@ -23394,7 +23404,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"ws@npm:^8.18.0":
+"ws@npm:^8.18.0, ws@npm:~8.20.1":
   version: 8.20.1
   resolution: "ws@npm:8.20.1"
   peerDependencies:
@@ -23409,21 +23419,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"ws@npm:~8.17.1":
-  version: 8.17.1
-  resolution: "ws@npm:8.17.1"
-  peerDependencies:
-    bufferutil: ^4.0.1
-    utf-8-validate: ">=5.0.2"
-  peerDependenciesMeta:
-    bufferutil:
-      optional: true
-    utf-8-validate:
-      optional: true
-  checksum: 10c0/f4a49064afae4500be772abdc2211c8518f39e1c959640457dcee15d4488628620625c783902a52af2dd02f68558da2868fd06e6fd0e67ebcd09e6881b1b5bfe
-  languageName: node
-  linkType: hard
-
 "xcase@npm:^2.0.1":
   version: 2.0.1
   resolution: "xcase@npm:2.0.1"