diff --git a/pkgs/applications/misc/synergy/default.nix b/pkgs/applications/misc/synergy/default.nix
index 5c1cce192163a..b0722e18eeaad 100644
--- a/pkgs/applications/misc/synergy/default.nix
+++ b/pkgs/applications/misc/synergy/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, lib, fetchFromGitHub, cmake, openssl, qttools
+{ stdenv, lib, fetchpatch, fetchFromGitHub, cmake, openssl, qttools
 , ApplicationServices, Carbon, Cocoa, CoreServices, ScreenSaver
 , xlibsWrapper, libX11, libXi, libXtst, libXrandr, xinput, avahi-compat
 , withGUI ? true, wrapQtAppsHook }:
@@ -14,7 +14,14 @@ stdenv.mkDerivation rec {
     sha256 = "1jk60xw4h6s5crha89wk4y8rrf1f3bixgh5mzh3cq3xyrkba41gh";
   };
 
-  patches = [ ./build-tests.patch
+  patches = [
+    ./build-tests.patch
+    (fetchpatch {
+      name = "CVE-2020-15117.patch";
+      url = "https://github.com/symless/synergy-core/commit/"
+          + "0a97c2be0da2d0df25cb86dfd642429e7a8bea39.patch";
+      sha256 = "03q8m5n50fms7fjfjgmqrgy9mrxwi9kkz3f3vlrs2x5h21dl6bmj";
+    })
   ] ++ lib.optional stdenv.isDarwin ./macos_build_fix.patch;
 
   # Since the included gtest and gmock don't support clang and the