Critical Unbound DNSSEC Validator Flaw Could Allow RCE via a Malicious DNS Zone

Every release of the Unbound DNS resolver before 1.26.1 has a critical heap overflow in its DNSSEC validator, maintainer NLnet Labs said in an advisory on Wednesday.

An attacker who controls a malicious zone and queries a vulnerable resolver can trigger it, enabling remote code execution.

Unbound 1.26.1, released the same day, fixes the bug, tracked as CVE-2026-81642, along with