diff --git a/ghost/admin/package.json b/ghost/admin/package.json
index cc72bba159..037600e907 100644
--- a/ghost/admin/package.json
+++ b/ghost/admin/package.json
@@ -117,7 +117,7 @@
     "normalize.css": "3.0.3",
     "postcss-color-mod-function": "3.0.3",
     "postcss-custom-media": "7.0.8",
-    "postcss-custom-properties": "8.0.11",
+    "postcss-custom-properties": "9.0.2",
     "postcss-easy-import": "3.0.0",
     "reframe.js": "2.2.5",
     "simplemde": "https://github.com/kevinansfield/simplemde-markdown-editor.git#ghost",
diff --git a/ghost/admin/yarn.lock b/ghost/admin/yarn.lock
index 7c51df99d8..954259128f 100644
--- a/ghost/admin/yarn.lock
+++ b/ghost/admin/yarn.lock
@@ -3507,7 +3507,7 @@ color-name@1.1.3:
   resolved "https://registry.yarnpkg.com/color-name/-/color-name-1.1.3.tgz#a7d0558bd89c42f795dd42328f740831ca53bc25"
   integrity sha1-p9BVi9icQveV3UIyj3QIMcpTvCU=
 
-color-name@^1.0.0:
+color-name@^1.0.0, color-name@^1.1.4:
   version "1.1.4"
   resolved "https://registry.yarnpkg.com/color-name/-/color-name-1.1.4.tgz#c2a09a87acbde69543de6f63fa3995c826c536a2"
   integrity sha512-dOy+3AuW3a2wNbZHIuMZpTcgjGuLU/uBL/ubcZF9OXbDo8ff4O8yVp5Bf0efS8uEoYo5q4Fx7dY9OgQGXgAsQA==
@@ -7256,6 +7256,11 @@ invariant@^2.2.2:
   dependencies:
     loose-envify "^1.0.0"
 
+ip-regex@^4.1.0:
+  version "4.1.0"
+  resolved "https://registry.yarnpkg.com/ip-regex/-/ip-regex-4.1.0.tgz#5ad62f685a14edb421abebc2fff8db94df67b455"
+  integrity sha512-pKnZpbgCTfH/1NLIlOduP/V+WRXzC2MOz3Qo8xmxk8C5GudJLgK5QyLVXOSWy3ParAH7Eemurl3xjv/WXYFvMA==
+
 ipaddr.js@1.9.0:
   version "1.9.0"
   resolved "https://registry.yarnpkg.com/ipaddr.js/-/ipaddr.js-1.9.0.tgz#37df74e430a0e47550fe54a2defe30d8acd95f65"
@@ -7428,6 +7433,11 @@ is-number@^3.0.0:
   dependencies:
     kind-of "^3.0.2"
 
+is-number@^7.0.0:
+  version "7.0.0"
+  resolved "https://registry.yarnpkg.com/is-number/-/is-number-7.0.0.tgz#7535345b896734d5f80c4d06c50955527a14f12b"
+  integrity sha512-41Cifkg6e8TylSpdtTpeLVMqvSBEVzTttHvERD741+pnZ8ANv0004MRL43QKPDlK9cGvNp6NZWZUBlbGXYxxng==
+
 is-obj@^1.0.0:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/is-obj/-/is-obj-1.0.1.tgz#3e4729ac1f5fde025cd7d83a896dab9f4f67db0f"
@@ -7510,6 +7520,13 @@ is-typedarray@~1.0.0:
   resolved "https://registry.yarnpkg.com/is-typedarray/-/is-typedarray-1.0.0.tgz#e479c80858df0c1b11ddda6940f96011fcda4a9a"
   integrity sha1-5HnICFjfDBsR3dppQPlgEfzaSpo=
 
+is-url-superb@^3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/is-url-superb/-/is-url-superb-3.0.0.tgz#b9a1da878a1ac73659047d1e6f4ef22c209d3e25"
+  integrity sha512-3faQP+wHCGDQT1qReM5zCPx2mxoal6DzbzquFlCYJLWyy4WPTved33ea2xFbX37z4NoriEwZGIYhFtx8RUB5wQ==
+  dependencies:
+    url-regex "^5.0.0"
+
 is-utf8@^0.2.0:
   version "0.2.1"
   resolved "https://registry.yarnpkg.com/is-utf8/-/is-utf8-0.2.1.tgz#4b0da1442104d1b336340e80797e865cf39f7d72"
@@ -9735,13 +9752,13 @@ postcss-custom-media@7.0.8:
   dependencies:
     postcss "^7.0.14"
 
-postcss-custom-properties@8.0.11:
-  version "8.0.11"
-  resolved "https://registry.yarnpkg.com/postcss-custom-properties/-/postcss-custom-properties-8.0.11.tgz#2d61772d6e92f22f5e0d52602df8fae46fa30d97"
-  integrity sha512-nm+o0eLdYqdnJ5abAJeXp4CEU1c1k+eB2yMCvhgzsds/e0umabFrN6HoTy/8Q4K5ilxERdl/JD1LO5ANoYBeMA==
+postcss-custom-properties@9.0.2:
+  version "9.0.2"
+  resolved "https://registry.yarnpkg.com/postcss-custom-properties/-/postcss-custom-properties-9.0.2.tgz#091aefaa309826302d53ec6d780fbe1df8f40fd4"
+  integrity sha512-WHaQrEp3gJ6mgxBA4mGJKW6DSVfy2IFnKPFAb2IEulgxGUW8nWp1NkOD/rWR6e2uIuAdnTa0LXSupST7daniAw==
   dependencies:
     postcss "^7.0.17"
-    postcss-values-parser "^2.0.1"
+    postcss-values-parser "^3.0.5"
 
 postcss-discard-comments@^4.0.2:
   version "4.0.2"
@@ -10015,7 +10032,7 @@ postcss-value-parser@^4.0.0:
   resolved "https://registry.yarnpkg.com/postcss-value-parser/-/postcss-value-parser-4.0.0.tgz#99a983d365f7b2ad8d0f9b8c3094926eab4b936d"
   integrity sha512-ESPktioptiSUchCKgggAkzdmkgzKfmp0EU8jXH+5kbIUB+unr0Y4CY9SRMvibuvYUBjNh1ACLbxqYNpdTQOteQ==
 
-postcss-values-parser@^2.0.0, postcss-values-parser@^2.0.1:
+postcss-values-parser@^2.0.0:
   version "2.0.1"
   resolved "https://registry.yarnpkg.com/postcss-values-parser/-/postcss-values-parser-2.0.1.tgz#da8b472d901da1e205b47bdc98637b9e9e550e5f"
   integrity sha512-2tLuBsA6P4rYTNKCXYG/71C7j1pU6pK503suYOmn4xYrQIzW+opD+7FAFNuGSdZC/3Qfy334QbeMu7MEb8gOxg==
@@ -10024,6 +10041,17 @@ postcss-values-parser@^2.0.0, postcss-values-parser@^2.0.1:
     indexes-of "^1.0.1"
     uniq "^1.0.1"
 
+postcss-values-parser@^3.0.5:
+  version "3.0.5"
+  resolved "https://registry.yarnpkg.com/postcss-values-parser/-/postcss-values-parser-3.0.5.tgz#9f83849fb89eaac74c2d5bf75e8e9715508a8c8d"
+  integrity sha512-0N6EUBx2Vzl0c9LQipuus90EkVh7saBQFRhgAYpHHcDCIvxRt+K/q0zwcIYtDQVNs5Y9NGqei4AuCEvAOsePfQ==
+  dependencies:
+    color-name "^1.1.4"
+    is-number "^7.0.0"
+    is-url-superb "^3.0.0"
+    postcss "^7.0.5"
+    url-regex "^5.0.0"
+
 postcss@^6.0.1, postcss@^6.0.11:
   version "6.0.23"
   resolved "https://registry.yarnpkg.com/postcss/-/postcss-6.0.23.tgz#61c82cc328ac60e677645f979054eb98bc0e3324"
@@ -11764,6 +11792,11 @@ tiny-lr@^1.1.1:
     object-assign "^4.1.0"
     qs "^6.4.0"
 
+tlds@^1.203.0:
+  version "1.203.1"
+  resolved "https://registry.yarnpkg.com/tlds/-/tlds-1.203.1.tgz#4dc9b02f53de3315bc98b80665e13de3edfc1dfc"
+  integrity sha512-7MUlYyGJ6rSitEZ3r1Q1QNV8uSIzapS8SmmhSusBuIc7uIxPPwsKllEP0GRp1NS6Ik6F+fRZvnjDWm3ecv2hDw==
+
 tmp@0.0.28:
   version "0.0.28"
   resolved "https://registry.yarnpkg.com/tmp/-/tmp-0.0.28.tgz#172735b7f614ea7af39664fa84cf0de4e515d120"
@@ -12099,6 +12132,14 @@ url-parse-lax@^3.0.0:
   dependencies:
     prepend-http "^2.0.0"
 
+url-regex@^5.0.0:
+  version "5.0.0"
+  resolved "https://registry.yarnpkg.com/url-regex/-/url-regex-5.0.0.tgz#8f5456ab83d898d18b2f91753a702649b873273a"
+  integrity sha512-O08GjTiAFNsSlrUWfqF1jH0H1W3m35ZyadHrGv5krdnmPPoxP27oDTqux/579PtaroiSGm5yma6KT1mHFH6Y/g==
+  dependencies:
+    ip-regex "^4.1.0"
+    tlds "^1.203.0"
+
 url-to-options@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/url-to-options/-/url-to-options-1.0.1.tgz#1505a03a289a48cbd7a434efbaeec5055f5633a9"