๐Ÿ” CVE Alert

CVE-2026-12617

HIGH 7.5

Record ordering based unexpected exit with CNAME or DNAME

CVSS Score
7.5
EPSS Score
0.0%
EPSS Percentile
0th

The issue is unexpected program termination based on ordering and/or specific content in responses to queries for CNAME or DNAME, and A records. Specifically, if a client queries for a DNAME and A record below the DNAME to the resolver, and the authoritative server responds positively to the A query but delays the DNAME response and later responds negatively, `named` may quit unexpectedly. Or, if a client queries for a CNAME and A record for the same name to the resolver, and the authoritative server responds positively to the A query but delays the CNAME response and later responds with a self-referential CNAME, the same failure may occur. This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.24, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1.

CWE CWE-617
Vendor isc
Product bind 9
Published Jul 22, 2026
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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Affected Versions

ISC / BIND 9
9.18.0 โ‰ค 9.18.50 9.20.0 โ‰ค 9.20.24 9.18.11-S1 โ‰ค 9.18.50-S1 9.20.9-S1 โ‰ค 9.20.24-S1

References

NVD โ†— CVE.org โ†— EPSS Data โ†—
kb.isc.org: https://kb.isc.org/docs/cve-2026-12617 downloads.isc.org: https://downloads.isc.org/isc/bind9/9.20.26

Credits

ISC would like to thank Qifan Zhang of Palo Alto Networks for bringing this vulnerability to our attention.