What is CVE-2026-66374?

CVE-2026-66374 is a high-severity vulnerability in Nic Knot Resolver, classified under Improper Validation of Specified Quantity in Input. CVSS score: 8.1/10. Published 2026-07-25.

How severe is CVE-2026-66374?

High severity. CVSS v3 base score is 8.1 out of 10.

Is CVE-2026-66374 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Nic Knot Resolver

CVE-2026-66374

Knot Resolver before 6.4.1 allows remote code execution via a heap-based buffer overflow in the DoQ (DNS-over-QUIC) receive path.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:L.

Affected products

Nic Knot Resolver — versions 0

Weakness classification (CWE)

CWE-1284 — Improper Validation of Specified Quantity in Input

Public proof-of-concept exploits

venglin/knot-doq

References

cve@mitre.org
cve@mitre.org

Frequently asked questions

What is CVE-2026-66374?: CVE-2026-66374 is a high-severity vulnerability in Nic Knot Resolver, classified under Improper Validation of Specified Quantity in Input. CVSS score: 8.1/10. Published 2026-07-25.
How severe is CVE-2026-66374?: High severity. CVSS v3 base score is 8.1 out of 10.
Is CVE-2026-66374 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.