dns/bind9* -- Heavy DNSSEC Validation Load Can Cause a 'Bad Cache' Assertion Failure

ISC reports:

High numbers of queries with DNSSEC validation enabled can
cause an assertion failure in named, caused by using a ‘bad cache’
data structure before it has been initialized.
BIND 9 stores a cache of query names that are known to be failing due
to misconfigured name servers or a broken chain of trust. Under high query
loads when DNSSEC validation is active, it is possible for a condition
to arise in which data from this cache of failing queries could be used
before it was fully initialized, triggering an assertion failure.
This bug cannot be encountered unless your server is doing DNSSEC
validation.