High severity · published Sep 16, 2026
CVE-2026-80274
Validating resolver can abort while caching a mismatched NOQNAME proof
7.5
CVSS
0.6%
EPSS
No
On KEV
Description
If a BIND resolver sends a query for a DNSSEC-signed authoritative zone, and the authoritative server replies with a valid wildcard answer and signed NSEC3 proof, followed by an unsigned NSEC at the same owner name, it will trigger an unexpected program exit. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 47% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
B9
BIND 9 · ISC
9.11.0 through 9.18.50; 9.20.0 through 9.20.27; 9.21.0 through 9.21.25; 9.11.3-S1 through 9.18.50-S1; 9.20.9-S1 through 9.20.27-S1 · source: vendor
Affected product
B9
BIND 9
ISC
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