Please refer CHANGES file for complete changes and here is quote from
release announce.
Introduction
BIND 9.6-ESV-R9-P1 is the latest production release of BIND 9.6-ESV.
Security Fixes
Prevents exploitation of a runtime_check which can crash named
when satisfying a recursive query for particular malformed zones.
(CVE-2013-3919) [RT #33690]
Prevents a named assert (crash) when validating caused by using
"Bad cache" data before it has been initialized. [CVE-2012-3817]
[RT #30025]
A condition has been corrected where improper handling of
zero-length RDATA could cause undesirable behavior, including
termination of the named process. [CVE-2012-1667] [RT #29644]
New Features
Adds a new configuration option, "check-spf"; valid values are
"warn" (default) and "ignore". When set to "warn", checks SPF
and TXT records in spf format, warning if either resource record
type occurs without a corresponding record of the other resource
record type. [RT #33355]
Adds support for Uniform Resource Identifier (URI) resource
records. [RT #23386]
Adds support for Host Identity Protocol (HIP) resource records
[RT #19384]
Adds support for the EUI48 and EUI64 RR types. [RT #33082]
Adds support for the RFC 6742 ILNP record types (NID, LP, L32,
and L64). [RT #31836]
The contributed queryperf utility has been improved, now retaining
better round trip time statistics. [RT #30128]
26ced77591