3.2.6.6 fixes a few semi-critical bugs that were introduced around version 3.2.6.2. These bugs deal with applying content permissions. Affected content permission modules are redirects, javascript and plugins.
Thanks to core fixes in Thunderbird (since about version 2 [though it might be earlier]), remote javascript cannot access high level elements (this means your emails, window chrome, etc).
If you use Thunderbird 3.0b4pre or higher, you are confirmed safe (as content permissions have been moved to core since that version).
I apologize for any problems this may have caused. This build has been uploaded to AMO and put on urgent release. In the meantime, you can download it here.
The tabs build has been updated. You can get it here.
