Update CHANGELOG.md

Author: ramsessanchez

CHANGELOG.md

@@ -11,6 +11,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+## [5.67.0] - 2023-08-10
+
+### Added 
+
+- ChatMessageSetReaction derived types and requests.
+- ChatMessageUnsetReaction derived types and requests.
+- CustomSecurityAttributeValue model.
+- MeetingChatHistoryDefaultMode model. 
+
 ## [5.66.0] - 2023-07-28
 
 ### Added