diff --git a/pkgs/applications/networking/browsers/firefox/packages/firefox.nix b/pkgs/applications/networking/browsers/firefox/packages/firefox.nix
index c9742c6ac01a..33304d10dae5 100644
--- a/pkgs/applications/networking/browsers/firefox/packages/firefox.nix
+++ b/pkgs/applications/networking/browsers/firefox/packages/firefox.nix
@@ -9,10 +9,10 @@
 
 buildMozillaMach rec {
   pname = "firefox";
-  version = "143.0.1";
+  version = "143.0.3";
   src = fetchurl {
     url = "mirror://mozilla/firefox/releases/${version}/source/firefox-${version}.source.tar.xz";
-    sha512 = "ef00d8bab715e7c2f4c138cfce0698e004f0616c767c8a7fa918e24e4a9f9151c41184d9c089ccbc6ab46a3b4bf6f12d723196f47e9c9d7f55f2ca44bab17cb2";
+    sha512 = "c092bd3aac79f856a804c908b76d40409ce052b00176269ea3029b5a3a6885d4d21ce26bd76c9ea13827ff75459b6b4b0566f5aa49035ac234ae5890c67845b0";
   };
 
   meta = {