Changelog: Add an entry for #2817

Author: mssalvatore

CHANGELOG.md

@@ -19,6 +19,8 @@ Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Security
 - Fixed plaintext private key in SSHKey pair list in UI. #2950
 - MongoDB version from 4.x to 6.0.4. #2706
+- Replaced the `SystemSingleton` component, which could allow local users to
+  execute a DoS attack against agents. #2817
 
 ## [2.0.0] - 2023-02-08
 ### Added