named could crash during recursive processing of DNAME records when deny-answer-aliases was in use. This flaw is disclosed in CVE-2018-5740. [GL #387]

When recursion is enabled but the allow-recursion and allow-query-cache ACLs are not specified, they should be limited to local networks, but they were inadvertently set to match the default allow-query, thus allowing remote queries. This flaw is disclosed in CVE-2018-5738. [GL #309]

The serve-stale feature could cause an assertion failure in rbtdb.c even when stale-answer-enable was false. The simultaneous use of stale cache records and NSEC aggressive negative caching could trigger a recursion loop in the named process. This flaw is disclosed in CVE-2018-5737. [GL #185]

A bug in zone database reference counting could lead to a crash when multiple versions of a slave zone were transferred from a master in close succession. This flaw is disclosed in CVE-2018-5736. [GL #134]

update-policy rules that otherwise ignore the name field now require that it be set to "." to ensure that any type list present is properly interpreted. Previously, if the name field was omitted from the rule declaration but a type list was present, it wouldn't be interpreted as expected.

named now supports the "root key sentinel" mechanism. This enables validating resolvers to indicate which trust anchors are configured for the root, so that information about root key rollover status can be gathered. To disable this feature, add root-key-sentinel no; to named.conf. [GL #37]

Add the ability to not return a DNS COOKIE option when one is present in the request. To prevent a cookie being returned add answer-cookie no; to named.conf. [GL #173]

answer-cookie no is only intended as a temporary measure, for use when named shares an IP address with other servers that do not yet support DNS COOKIE. A mismatch between servers on the same address is not expected to cause operational problems, but the option to disable COOKIE responses so that all servers have the same behavior is provided out of an abundance of caution. DNS COOKIE is an important security mechanism, and should not be disabled unless absolutely necessary.

BIND now can be compiled against libidn2 library to add IDNA2008 support. Previously BIND only supported IDNA2003 using (now obsolete) idnkit-1 library.

dig +noidnin can be used to disable IDN processing on the input domain name, when BIND is compiled with IDN support.

named now rejects excessively large incremental (IXFR) zone transfers in order to prevent possible corruption of journal files which could cause named to abort when loading zones. [GL #339]