diff --git a/CHANGELOG b/CHANGELOG
index 3de9f620f..ce621c619 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -3,7 +3,8 @@ This is the changelog file for the POCO C++ Libraries.
 Release 1.12.3 (2022-10-31)
 ===========================
 
-- TODO
+- GH #3849: Upgrade bundled libexpat to 2.5.0 [fixes CVE]
+- GH #3852: SocketReactor - 100 % CPU usage on single-core system
 
 
 Release 1.12.3 (2022-10-24)
diff --git a/doc/99100-ReleaseNotes.page b/doc/99100-ReleaseNotes.page
index fc83690a4..9ce7cc2fb 100644
--- a/doc/99100-ReleaseNotes.page
+++ b/doc/99100-ReleaseNotes.page
@@ -6,7 +6,8 @@ AAAIntroduction
 
 !!Summary of Changes
 
-  - TODO
+  - GH #3849: Upgrade bundled libexpat to 2.5.0 [fixes CVE]
+  - GH #3852: SocketReactor - 100 % CPU usage on single-core system
 
 
 !!!Release 1.12.3