The Perl_reg_numbered_buff_fetch function in Perl 5.10.0, 5.12.0, 5.14.0, and other versions, when running with debugging enabled, allows context-dependent attackers to cause a denial of service (assertion failure and application exit) via crafted input that is not properly handled when using certain regular expressions, as demonstrated by causing SpamAssassin and OCSInventory to crash.
https://rt.perl.org/Public/Bug/Display.html?id=76538
https://listi.jpberlin.de/pipermail/postfixbuch-users/2011-February/055885.html
https://bugzilla.redhat.com/show_bug.cgi?id=694166
http://lists.opensuse.org/opensuse-updates/2011-05/msg00025.html
http://lists.opensuse.org/opensuse-security-announce/2011-05/msg00005.html