CVE-2026-3591 — A stack use-after-return flaw in SIG(0) handling code may enable ACL bypass

Affected: ISC BIND 9

A use-after-return vulnerability exists in the `named` server when handling DNS queries signed with SIG(0). Using a specially-crafted DNS request, an attacker may be able to cause an ACL to improperly (mis)match an IP address. In a default-allow ACL (denying only specific IP addresses), this may lead to unauthorized access. Default-deny ACLs should fail-secure. This issue affects BIND 9 versions 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, and 9.20.9-S1 through 9.20.20-S1. BIND 9 versions 9.18.0 through 9.18.46 and 9.18.11-S1 through 9.18.46-S1 are NOT affected.

USN-8124-1 — bind9 vulnerabilities

Affected: Ubuntu:22.04:LTS: bind9, Ubuntu:24.04:LTS: bind9, Ubuntu:25.10: bind9

Samy Medjahed discovered that Bind incorrectly handled insecure delegation validation. A remote attacker could possibly use this issue to cause excessive NSEC3 iterations, consuming CPU resources, and leading to a denial of service. (CVE-2026-1519)

Vitaly Simonovich discovered that Bind incorrectly handled memory when preparing DNSSEC proofs of non-existence. A remote attacker could possibly use this issue to cause memory consumption, leading to a denial of service. This issue only affected Ubuntu 25.10. (CVE-2026-3104)

Vitaly Simonovich discovered that Bind incorrectly handled authenticated queries containing TKEY records. A remote attacker could possibly use this issue to cause Bind to crash, resulting in a denial of service. This issue only affected Ubuntu 25.10. (CVE-2026-3119)

It was discovered that Bind incorrectly handled DNS queries signed with SIG(0). A remote attacker could possibly use this issue to bypass ACLs. This issue only affected Ubuntu 25.10. (CVE-2026-3591)

Most recent entries from all

CVE-2026-3591 — A stack use-after-return flaw in SIG(0) handling code may enable ACL bypass

USN-8124-1 — bind9 vulnerabilities