Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2026-5946

37
FAUCET Score

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.

First published: May 20, 2026Last modified: May 20, 2026

Impacted Technologies

VendorProductVersion(s)CPE
>= 9.11.0, <= 9.16.50CPE matchmatch criteria
cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*
>= 9.18.0, < 9.18.49CPE matchmatch criteria
cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*
>= 9.20.0, < 9.20.23CPE matchmatch criteria
cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*
>= 9.21.0, < 9.21.22CPE matchmatch criteria
cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*

CVSS Data

CVSS version used by this source: 3.1

7.5HIGH

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 Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
Exploitability Score
3.9
Impact Score
3.6
CvssVersion
3.1

Exploit Intelligence

EPSS Score
1.87%
Probability of exploitation in next 30 days
EPSS Percentile
77.2%
Percentile rank of EPSS score among Peer Group
As of 2026-07-26
Model: v2026.06.15
This CVE's current EPSS score of 0.0187 is in the 60th percentile among its peer group of 51,485 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 GitHub mentions.

Media Mentions

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (6)

microsoftpatch availablevia msrc
Product: 21351-17084Fixed in: 9.20.23-1
microsoftpatch availablevia msrc
Product: azl3 bind 9.20.21-1 on Azure Linux 3.0Fixed in: 9.20.23-1
ubuntupatch availablevia ubuntu_usn
Product: bind9 (jammy)Fixed in: 1:9.18.39-0ubuntu0.22.04.4
ubuntupatch availablevia ubuntu_usn
Product: bind9 (noble)Fixed in: 1:9.18.39-0ubuntu0.24.04.5
ubuntupatch availablevia ubuntu_usn
Product: bind9 (questing)Fixed in: 1:9.20.11-1ubuntu2.4
ubuntupatch availablevia ubuntu_usn
Product: bind9 (resolute)Fixed in: 1:9.20.18-1ubuntu2.1

Vendor Advisories (2)

ubuntuUSN-8293-1

Bind vulnerabilities

May 21, 2026
microsoft2026-May/CVE-2026-5946Important

Invalid handling of CLASS != IN

May 12, 2026

References

access.redhat.com / errata/RHSA-2026:20334
access.redhat.com / errata/RHSA-2026:23360
access.redhat.com / errata/RHSA-2026:24338
access.redhat.com / errata/RHSA-2026:24339
access.redhat.com / errata/RHSA-2026:24367
access.redhat.com / errata/RHSA-2026:24368
access.redhat.com / security/cve/CVE-2026-5946
bugzilla.redhat.com / show_bug.cgi
security.access.redhat.com / data/csaf/v2/vex/2026/cve-2026-5946.json
downloads.isc.org / isc/bind9/9.18.49
Patch
downloads.isc.org / isc/bind9/9.20.23
Patch
downloads.isc.org / isc/bind9/9.21.22
Patch
kb.isc.org / docs/cve-2026-5946
Vendor Advisory