CVE-2026-5946
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.87%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 1.87% probability · 78th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-20, CWE-125, CWE-617, CWE-754, CWE-843, CWE-1287
- Affected
- isc/bind
- Source
- security-officer@isc.org
References
- https://downloads.isc.org/isc/bind9/9.18.49Patch
- https://downloads.isc.org/isc/bind9/9.20.23Patch
- https://downloads.isc.org/isc/bind9/9.21.22Patch
- https://kb.isc.org/docs/cve-2026-5946Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:20334
- https://access.redhat.com/errata/RHSA-2026:23360
- https://access.redhat.com/errata/RHSA-2026:24338
- https://access.redhat.com/errata/RHSA-2026:24339
- https://access.redhat.com/errata/RHSA-2026:24367
- https://access.redhat.com/errata/RHSA-2026:24368
- https://access.redhat.com/errata/RHSA-2026:55441
- https://access.redhat.com/errata/RHSA-2026:57189
- https://access.redhat.com/errata/RHSA-2026:60383
- https://access.redhat.com/errata/RHSA-2026:62549
- https://access.redhat.com/security/cve/CVE-2026-5946
- https://bugzilla.redhat.com/show_bug.cgi?id=2479771
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-5946.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.