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VulnerabilityCVE-2026-5946Published 2026-05-20

CVE-2026-5946 — ISC BIND 9

high

As of 2026-05-20, CVE-2026-5946 is a HIGH-severity vulnerability in ISC BIND 9, CVSS v3.1 7.5, EPSS 0.0% (21.0th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-5946, most recently “BIND 9 Multi-CVE Disclosure (May 2026) — Heap UAF in DoH (CVE-2026-3593), SIG(0) UAF (CVE-2026-5947), Resolver Resend Loop DoS (CVE-2026-5950), CLASS!=IN Assertion DoS (CVE-2026-5946), Glue Amplification (CVE-2026-3592), GSS-API TKEY Memory Exhaustion (CVE-2026-3039)”.

CVSS v3.1
7.5/10High
EPSS
0.0%Higher than 21.0% of scored CVEs
CISA KEV
NoNot in the KEV catalog
Tracked threats
1Campaigns referencing it
Priority
4.6/10Threadlinqs triage score
Published
CVSS v3.1 7.5 (HIGH) · EPSS 0.0% (higher than 21.0% of all scored CVEs) · Priority 4.6/10 · Published 2026-05-20

Last updated:

What is 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. 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.

The record classifies CVE-2026-5946 under weakness classes CWE-20, CWE-125, CWE-617, CWE-754, CWE-843. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 138 days ago.

Severity and exploitation probability

CVSS v3.1 base score
7.5 — HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS (FIRST)
0.0% probability of exploitation in the next 30 days, higher than 21.0% of all scored CVEs
CISA KEV
Not listed in the CISA Known Exploited Vulnerabilities catalog
Threadlinqs priority
4.6/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
Published
2026-05-20

Is CVE-2026-5946 being exploited?

It currently carries a trending score of 10 in the Threadlinqs vulnerability feed.

Affected products and versions

How to fix CVE-2026-5946

No vendor patch reference has been recorded for CVE-2026-5946 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

Threat activity tracking CVE-2026-5946

1 tracked threat in the Threadlinqs corpus references CVE-2026-5946, either in the campaign’s CVE list or as an indicator on the campaign record.

Sources

Seeded from cveorg and not yet processed by the Threadlinqs enrichment pipeline, so blank CVSS, EPSS or KEV fields above mean NOT MEASURED rather than measured-absent.