bbPress 2.5.7 is out now, and it fixes several issues regarding unescaped URL output for all previous bbPress 2.x installations. If you’re using any version of bbPress 2.x and have not yet updated, please do so right away. If you need help, please reach out in our support forums and someone will be happy to assist you.
The bbPress team worked closely with the WordPress core team and several other plugin authors to coordinate the release of 2.5.7 alongside other libraries with similar issues.
These fixes have also been ported over to 2.6, which we continue to run here at bbPress.org and BuddyPress.org.