Version 2.5.5 is a BuddyPress security release.
For Version 2.5.5, the database version (bp_db_version in wp_options) was 10803, and the Trac revision was r11502.
- Improved nonce protection for some front-end AJAX endpoints.
- Nonce protection for XProfile group & field actions.
- Nonce protection for canceling email change.
- Improve nonce checks for activity favoriting/unfavoriting.
See blog post https://buddypress.org/2017/03/buddypress-2-8-2-security-release/.