CVE-2026-5946 (GCVE-0-2026-5946)

Vulnerability from cvelistv5 – Published: 2026-05-20 13:10 – Updated: 2026-05-20 13:40
VLAI?
Title
Invalid handling of CLASS != IN
Summary
Multiple flaws have been identified in `named` related to the handling of DNS messages whose CLASS is not Internet (`IN`) — for example, `CHAOS` or `HESIOD`, or DNS messages that specify meta-classes (`ANY` or `NONE`) in the question section. Specially crafted requests reaching the affected code paths — recursion, dynamic updates (`UPDATE`), zone change notifications (`NOTIFY`), or processing of `IN`-specific record types in non-`IN` data — can cause assertion failures in `named`. This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.48, 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1.
Severity ?
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
  • CWE-20 - Improper Input Validation
  • CWE-125 - Out-of-bounds Read
  • CWE-617 - Reachable Assertion
  • CWE-754 - Improper Check for Unusual or Exceptional Conditions
  • CWE-843 - Access of Resource Using Incompatible Type ('Type Confusion')
Assigner
isc
References
Impacted products
Vendor Product Version
ISC BIND 9 Affected: 9.11.0 , ≤ 9.16.50 (custom)
Affected: 9.18.0 , ≤ 9.18.48 (custom)
Affected: 9.20.0 , ≤ 9.20.22 (custom)
Affected: 9.21.0 , ≤ 9.21.21 (custom)
Affected: 9.11.3-S1 , ≤ 9.16.50-S1 (custom)
Affected: 9.18.11-S1 , ≤ 9.18.48-S1 (custom)
Affected: 9.20.9-S1 , ≤ 9.20.22-S1 (custom)
Create a notification for this product.
Date Public ?
2026-05-20 00:00
Credits
ISC would like to thank Mcsky23 for bringing this vulnerability to our attention.
Show details on NVD website
To clipboard 

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Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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