log_blackbox.c in libqb before 2.0.8 allows a buffer overflow via long log messages because the header size is not considered.
https://github.com/ClusterLabs/libqb/pull/490
https://github.com/ClusterLabs/libqb/compare/v2.0.7...v2.0.8
https://github.com/ClusterLabs/libqb/commit/1bbaa929b77113532785c408dd1b41cd0521ffc8