diff --git a/pkgs/by-name/ti/tinyproxy/package.nix b/pkgs/by-name/ti/tinyproxy/package.nix
index 9ab1e4826f0c..035c3194b91e 100644
--- a/pkgs/by-name/ti/tinyproxy/package.nix
+++ b/pkgs/by-name/ti/tinyproxy/package.nix
@@ -2,6 +2,7 @@
   lib,
   stdenv,
   fetchFromGitHub,
+  fetchpatch2,
   autoreconfHook,
   perl,
   nixosTests,
@@ -19,6 +20,15 @@ stdenv.mkDerivation (finalAttrs: {
     owner = "tinyproxy";
   };
 
+  patches = [
+    # Fix case-sensitive matching of "chunked" (CVE-2026-31842)
+    (fetchpatch2 {
+      name = "fix-chunked-case-sensitivity.patch";
+      url = "https://github.com/tinyproxy/tinyproxy/commit/879bf844abffa0bf5fae6aff0c73179024dd9f98.patch";
+      hash = "sha256-Nav3nXyxdoM/tIvfyPJHEYEjAtrRrJlvkMXzsQCZan4=";
+    })
+  ];
+
   # perl is needed for man page generation.
   nativeBuildInputs = [
     autoreconfHook