Upgrade to 9.8.3-P1, the latest from ISC. This version contains

Upgrade to 9.8.3-P1, the latest from ISC. This version contains
a critical bugfix:

  Processing of DNS resource records where the rdata field is zero length
  may cause various issues for the servers handling them.

  Processing of these records may lead to unexpected outcomes. Recursive
  servers may crash or disclose some portion of memory to the client.
  Secondary servers may crash on restart after transferring a zone
  containing these records. Master servers may corrupt zone data if the
  zone option "auto-dnssec" is set to "maintain". Other unexpected
  problems that are not listed here may also be encountered.

All BIND users are strongly encouraged to upgrade.