diff --git a/pkgs/development/libraries/polkit/default.nix b/pkgs/development/libraries/polkit/default.nix
index dcc077e3dd8d..3a3199cbd7a9 100644
--- a/pkgs/development/libraries/polkit/default.nix
+++ b/pkgs/development/libraries/polkit/default.nix
@@ -60,6 +60,11 @@ stdenv.mkDerivation rec {
       url = "https://gitlab.freedesktop.org/polkit/polkit/-/commit/7ba07551dfcd4ef9a87b8f0d9eb8b91fabcb41b3.patch";
       sha256 = "ebbLILncq1hAZTBMsLm+vDGw6j0iQ0crGyhzyLZQgKA=";
     })
+    # pkexec: local privilege escalation (CVE-2021-4034)
+    (fetchpatch {
+      url = "https://gitlab.freedesktop.org/polkit/polkit/-/commit/a2bf5c9c83b6ae46cbd5c779d3055bff81ded683.patch";
+      sha256 = "162jkpg2myq0rb0s5k3nfr4pqwv9im13jf6vzj8p5l39nazg5i4s";
+    })
   ] ++ lib.optionals stdenv.hostPlatform.isMusl [
     # Make netgroup support optional (musl does not have it)
     # Upstream MR: https://gitlab.freedesktop.org/polkit/polkit/merge_requests/10