diff --git a/core/base/Dockerfile b/core/base/Dockerfile
index 39d9f29c..5e3ad092 100644
--- a/core/base/Dockerfile
+++ b/core/base/Dockerfile
@@ -3,7 +3,7 @@
 # base system image (intermediate)
 # Note when updating the alpine tag, first manually run the workflow .github/workflows/mirror.yml.
 # Just run the workflow with the tag that must be synchronised.
-ARG DISTRO=ghcr.io/mailu/alpine:3.20
+ARG DISTRO=ghcr.io/mailu/alpine:3.20.3
 FROM $DISTRO as system
 
 ENV TZ=Etc/UTC LANG=C.UTF-8
diff --git a/towncrier/newsfragments/3622.misc b/towncrier/newsfragments/3622.misc
new file mode 100644
index 00000000..2e749d74
--- /dev/null
+++ b/towncrier/newsfragments/3622.misc
@@ -0,0 +1 @@
+Upgrade to alpine 3.20.3