Update Changelog

Author: byroot

CHANGES.md

@@ -11,7 +11,7 @@
 ### 2026-06-11 (2.19.9)
 
 * Fix buffer overflow that could lead to a crash when writing JSON directly into an IO
-  with `JSON.generate(object, io)`. [CVE-PENDING].
+  with `JSON.generate(object, io)`. [CVE-2026-54696].
 
 ### 2026-06-03 (2.19.8)