diff --git a/pkgs/development/python-modules/cleo/default.nix b/pkgs/development/python-modules/cleo/default.nix
index e81ff175d533..b0716b7e2f39 100644
--- a/pkgs/development/python-modules/cleo/default.nix
+++ b/pkgs/development/python-modules/cleo/default.nix
@@ -1,6 +1,7 @@
 { lib
 , buildPythonPackage
 , fetchFromGitHub
+, fetchpatch
 , crashtest
 , poetry-core
 , pylev
@@ -20,6 +21,15 @@ buildPythonPackage rec {
     hash = "sha256-FtGGIRF/tA2OWEjkCFwa1HHg6VY+5E5mAiJC/zjUC1g=";
   };
 
+  patches = [
+    (fetchpatch {
+      name = "CVE-2022-42966.patch";
+      url = "https://github.com/python-poetry/cleo/commit/b5b9a04d2caf58bf7cf94eb7ae4a1ebbe60ea455.patch";
+      relative = "src";
+      hash = "sha256-nMmRipgQC/w4GIV+VHgKx1xmPm4j+4tR980sROmbfnM=";
+    })
+  ];
+
   postPatch = ''
     substituteInPlace pyproject.toml \
       --replace 'crashtest = "^0.3.1"' 'crashtest = "*"'