diff --git a/pkgs/applications/networking/browsers/firefox/packages.nix b/pkgs/applications/networking/browsers/firefox/packages.nix
index 9fd1a2f1fcfb..e0c1f218c1e4 100644
--- a/pkgs/applications/networking/browsers/firefox/packages.nix
+++ b/pkgs/applications/networking/browsers/firefox/packages.nix
@@ -94,11 +94,11 @@
 
   firefox-esr-115 = buildMozillaMach rec {
     pname = "firefox-esr-115";
-    version = "115.11.0esr";
+    version = "115.12.0esr";
     applicationName = "Mozilla Firefox ESR";
     src = fetchurl {
       url = "mirror://mozilla/firefox/releases/${version}/source/firefox-${version}.source.tar.xz";
-      sha512 = "0f3a87c99fb008088afd509d9259f893fdd44ea6bf6a5e69806fefb8d355415e81b9e8832a392acb9d0c1c50e4add7f1362a4aaadc35e1d9c2e55baf7136aed8";
+      sha512 = "d98475061d870e0f3aa920b7c0b9b0c1cbdb3f4102f760f1d1c5ea3e45e216c673c8d3662501e7e78af4950a003a519e94b57e9b1eda8d615c159cdf62130e89";
     };
 
     meta = {