The version 5.7.2 was vulnerable to a heap corruption within the parsing of the PDU prior to the authentication process.
Created net-snmp tracking bugs for this issue:
Affects: fedora-all [bug 1552845]
The "upstream patch" linked in Comment 0 is the same as for Bug 1212408, which was CVE-2015-5621.
This issue has been addressed in the following products:
Red Hat Enterprise Linux 7
Red Hat Enterprise Linux 6
Via RHSA-2015:1636: https://access.redhat.com/errata/RHSA-2015:1636