Unbound vulnerabilities

Summary

Andrew Griffiths discovered that Unbound did not properly handle certain DNSCrypt packets. A remote attacker could possibly use this issue to cause Unbound to crash, resulting in a denial of service. (CVE-2026-32792) Qifan Zhang discovered that Unbound incorrectly handled DNSSEC validation in certain situations. A remote attacker could possibly use this issue to execute arbitrary code. This issue only affected Ubuntu 24.04 LTS, Ubuntu 25.10, and Ubuntu 26.04 LTS. (CVE-2026-33278) Qifan Zhang discovered that Unbound incorrectly handled certain ghost domain name records. A remote attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 24.04 LTS, Ubuntu 25.10, and Ubuntu 26.04 LTS. (CVE-2026-40622) Qifan Zhang discovered that Unbound did not properly limit processing of long EDNS option lists. A remote attacker could possibly use this issue to cause Unbound to use excessive resources, leading to a denial of service. (CVE-2026-41292) Qifan Zhang discovered that Unbound incorrectly handled jostle logic under certain circumstances. A remote attacker could possibly use this issue to cause Unbound to use excessive resources, leading to a denial of service. (CVE-2026-42534) Qifan Zhang discovered that Unbound did not properly bound NSEC3 hash calculations. A remote attacker could possibly use this issue to cause Unbound to use excessive resou Affected Ubuntu releases: 26.04, 25.10, 24.04, 22.04. CVEs: CVE-2026-33278, CVE-2026-42944, CVE-2026-40622, CVE-2026-42923, CVE-2026-44608, CVE-2026-41292, CVE-2026-42960, CVE-2026-42959….