diff --git a/ghost/admin/app/styles/components/codemirror.css b/ghost/admin/app/styles/components/codemirror.css
index afbdf21005..199f21b4af 100644
--- a/ghost/admin/app/styles/components/codemirror.css
+++ b/ghost/admin/app/styles/components/codemirror.css
@@ -14,5 +14,5 @@
 }
 
 .CodeMirror-linenumber {
-    min-width: 13px;
+    min-width: 14px;
 }
diff --git a/ghost/admin/package.json b/ghost/admin/package.json
index 83b7b5935f..149e36bbda 100644
--- a/ghost/admin/package.json
+++ b/ghost/admin/package.json
@@ -38,7 +38,7 @@
     "broccoli-merge-trees": "3.0.2",
     "broccoli-uglify-sourcemap": "2.2.0",
     "chai-dom": "1.8.1",
-    "codemirror": "5.39.0",
+    "codemirror": "5.42.2",
     "coveralls": "3.0.2",
     "csscomb": "4.2.0",
     "current-device": "0.7.8",
diff --git a/ghost/admin/yarn.lock b/ghost/admin/yarn.lock
index 46de1b91b8..45d7dc84ed 100644
--- a/ghost/admin/yarn.lock
+++ b/ghost/admin/yarn.lock
@@ -3629,10 +3629,10 @@ code-point-at@^1.0.0:
   resolved "https://registry.yarnpkg.com/code-point-at/-/code-point-at-1.1.0.tgz#0d070b4d043a5bea33a2f1a40e2edb3d9a4ccf77"
   integrity sha1-DQcLTQQ6W+ozovGkDi7bPZpMz3c=
 
-codemirror@5.39.0:
-  version "5.39.0"
-  resolved "https://registry.yarnpkg.com/codemirror/-/codemirror-5.39.0.tgz#4654f7d2f7e525e04a62e72d9482348ccb37dce5"
-  integrity sha512-vpJRray/0ZCt9FiS7UcVr1JAm6OBdUt6TA/94Q7MScr8TnutVdQWh/WPr0migzaBPQmYvY7I9UZNvbsaLESIuQ==
+codemirror@5.42.2:
+  version "5.42.2"
+  resolved "https://registry.yarnpkg.com/codemirror/-/codemirror-5.42.2.tgz#801ab715a7a7e1c7ed4162b78e9d8138b98de8f0"
+  integrity sha512-Tkv6im39VuhduFMsDA3MlXcC/kKas3Z0PI1/8N88QvFQbtOeiiwnfFJE4juGyC8/a4sb1BSxQlzsil8XLQdxRw==
 
 coffeescript@~1.10.0:
   version "1.10.0"
@@ -12222,7 +12222,7 @@ simple-swizzle@^0.2.2:
 
 "simplemde@https://github.com/kevinansfield/simplemde-markdown-editor.git#ghost":
   version "1.11.2"
-  resolved "https://github.com/kevinansfield/simplemde-markdown-editor.git#f41ae1c38827bbc93d337435f8f37bd1bf20d7ac"
+  resolved "https://github.com/kevinansfield/simplemde-markdown-editor.git#7afb50dcdd63d3a1f6ccad682b70acbd7bc52eb9"
 
 sinon@^7.1.1:
   version "7.2.2"