add details of security fix (#6822)

Author: TomWFox

CHANGELOG.md

@@ -6,7 +6,7 @@
 ### 4.3.0
 [Full Changelog](https://github.com/parse-community/parse-server/compare/4.2.0...4.3.0)
 - PERFORMANCE: Optimizing pointer CLP query decoration done by DatabaseController#addPointerPermissions [#6747](https://github.com/parse-community/parse-server/pull/6747). Thanks to [mess-lelouch](https://github.com/mess-lelouch).
-- SECURITY: Fix security breach on GraphQL viewer. Thanks to [Antoine Cormouls](https://github.com/Moumouls).
+- SECURITY: Fix security breach on GraphQL viewer [78239ac](https://github.com/parse-community/parse-server/commit/78239ac9071167fdf243c55ae4bc9a2c0b0d89aa), [secuity advisory](https://github.com/parse-community/parse-server/security/advisories/GHSA-236h-rqv8-8q73). Thanks to [Antoine Cormouls](https://github.com/Moumouls).
 - FIX: Save context not present if direct access enabled [#6764](https://github.com/parse-community/parse-server/pull/6764). Thanks to [Omair Vaiyani](https://github.com/omairvaiyani).
 - NEW: Before Connect + Before Subscribe [#6793](https://github.com/parse-community/parse-server/pull/6793). Thanks to [dblythy](https://github.com/dblythy).
 - FIX: Add version to playground to fix CDN [#6804](https://github.com/parse-community/parse-server/pull/6804). Thanks to [Antoine Cormouls](https://github.com/Moumouls).