Use-after-free vulnerability in ISC BIND 9.3.0 up to 9.3.3, 9.4.0a1 up to 9.4.0a6, 9.4.0b1 up to 9.4.0b4, 9.4.0rc1, and 9.5.0a1 (Bind Forum only) allows remote attackers to cause a denial of service (named daemon crash) via unspecified vectors that cause named to "dereference a freed fetch context."