diff --git a/Dockerfile b/Dockerfile
index f185d51..d33dc14 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -19,7 +19,7 @@ FROM jlesage/baseimage-gui:alpine-3.21-v4.7.1
 ARG DOCKER_IMAGE_VERSION=
 
 # Define software versions.
-ARG FIREFOX_VERSION=136.0-r0
+ARG FIREFOX_VERSION=136.0.4-r0
 #ARG PROFILE_CLEANER_VERSION=2.36
 
 # Define software download URLs.
diff --git a/appdefs.yml b/appdefs.yml
index 0c52b50..51bc3c0 100644
--- a/appdefs.yml
+++ b/appdefs.yml
@@ -102,6 +102,10 @@ app:
               for more details.
             - Make sure the kernel of your Linux distribution is up-to-date.
   changelog:
+    - version: 25.04.1
+      date: 2025-04-06
+      changes:
+        - 'Updated Firefox to version 136.0.4-r0.'
     - version: 25.03.1
       date: 2025-03-19
       changes: