CVE-2026-13321 DNSSEC Validation Bypass via Out-of-Zone NSEC Next Field
Attackers can bypass DNSSEC validation in BIND by exploiting out-of-zone NSEC records, potentially enabling DNS spoofing attacks.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-13321?
CVE-2026-13321 is a high-severity vulnerability in ISC BIND 9, published on 22 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
The BIND resolver accepts validly-signed NSEC records where the "Next Domain Name" field points outside the signer's zone. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1.
Weakness: CWE-346
Which versions are affected by CVE-2026-13321?
How do I fix CVE-2026-13321?
Apply the vendor's patch.
Is CVE-2026-13321 being exploited?
There is no known exploitation of CVE-2026-13321 in the wild and no public exploit code.
Sources
Also known as ALPINE-CVE-2026-13321, AZL-93123, BELL-CVE-2026-13321, CLSA-2026-1785885689, DEBIAN-CVE-2026-13321, ECHO-9d6e-b01e-b367 and 5 more.