From the ISC:

Description:

An as-yet unidentified network event caused BIND 9 resolvers to cache an invalid record, subsequent queries for which could crash the resolvers with an assertion failure. ISC is working on determining the ultimate cause by which a record with this particular inconsistency is cached.At this time we are making available a patch which makes named recover gracefully from the inconsistency, preventing the abnormal exit.

Response:
This vulnerability is not a threat for systems running the ASL Kernel. In addition we have release HIDS rule ID: 12149 to address this class of event as a level 12.

Updated bind* packages are also available, at least for EL4-6.