diff --git a/package.json b/package.json
index e9a2f98f..38d040dd 100644
--- a/package.json
+++ b/package.json
@@ -178,7 +178,7 @@
     "js-sequence-diagrams": "git+https://github.com/hedgedoc/js-sequence-diagrams.git",
     "jsonlint": "1.6.3",
     "keymaster": "1.6.2",
-    "less": "4.8.0",
+    "less": "4.9.0",
     "less-loader": "7.3.0",
     "list.js": "2.3.1",
     "mathjax": "2.7.9",
diff --git a/yarn.lock b/yarn.lock
index ae569992..83ff3340 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1537,7 +1537,7 @@ __metadata:
     jsdom: "npm:24.1.3"
     jsonlint: "npm:1.6.3"
     keymaster: "npm:1.6.2"
-    less: "npm:4.8.0"
+    less: "npm:4.9.0"
     less-loader: "npm:7.3.0"
     list.js: "npm:2.3.1"
     lodash: "npm:4.18.1"
@@ -9576,9 +9576,9 @@ __metadata:
   languageName: node
   linkType: hard
 
-"less@npm:4.8.0":
-  version: 4.8.0
-  resolution: "less@npm:4.8.0"
+"less@npm:4.9.0":
+  version: 4.9.0
+  resolution: "less@npm:4.9.0"
   dependencies:
     copy-anything: "npm:^3.0.5"
     errno: "npm:^0.1.1"
@@ -9606,7 +9606,7 @@ __metadata:
       optional: true
   bin:
     lessc: bin/lessc
-  checksum: 10/a2264aa6a028fc2a803d7d72689251d0bd8b516371903f566a0a956ec9975a6c62c3ed33fe61cf63f71820d654024f7e4552cac43963d6059048e75d79017afb
+  checksum: 10/61f8f40d0029dc411b3fae523c6d5d415e51f45cf48bb821febe8cbd0d03994884980c2dfd41af6e5307f7986fb931a84db20ec5e735d385eb8a40bc5cfe7eb7
   languageName: node
   linkType: hard