The mod_auth_mellon module before 0.8.1 allows remote attackers to obtain sensitive information or cause a denial of service (segmentation fault) via unspecified vectors related to a "session overflow" involving "sessions overlapping in memory."
https://postlister.uninett.no/sympa/arc/modmellon/2014-11/msg00000.html
https://github.com/UNINETT/mod_auth_mellon/releases/tag/v0.8.1
http://secunia.com/advisories/62125
http://secunia.com/advisories/62094