Older versions of BIND generally will not receive updates for new vulnerabilities. For more information, see ISC's Software Support Policy and Version Numbering.
SECURITY WARNING
Obsolete branches are all known to be vulnerable. ISC strongly recommends upgrading to a current version as soon as practical.
That said, the last-published matrix for a given branch is kept available for historical reference. Each major branch is given its own page. Click the link for a given version to see the details for that branch.