The am_read_post_data function in mod_auth_mellon before 0.11.1 does not limit the amount of data read, which allows remote attackers to cause a denial of service (worker process crash, web server deadlock, or memory consumption) via a large amount of POST data.
https://sympa.uninett.no/lists/uninett.no/arc/modmellon/2016-03/msg00000.html
https://github.com/UNINETT/mod_auth_mellon/pull/71
http://lists.fedoraproject.org/pipermail/package-announce/2016-March/179085.html