CVE-2026-66374: Knot Resolver before 6.4.1 allows remote code execution via a heap-based buffer overflow in the DoQ (DNS-over-

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HIGH 8.1REMOTE

CVE-2026-66374 is a high-severity flaw (CVSS 8.1) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

High severity
CISA SSVC: public proof of concept
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	8.1 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 51%)
CISA exploited list	No
Weakness	CWE-1284
Published	2026-07-25
Last modified	2026-10-24

Publisher (CNA): MITRE

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-07-25 01:16 UTCPublished CVE record published
2026-10-24 13:10 UTCUpdated Record last modified

Exact fixes by distribution

Fedora 46 · gnome-shell-extension-tiling-assistant · FIXED · 56-1.fc46 · FEDORA-2026-ebf66a5321 · source

sudo dnf upgrade --advisory=FEDORA-2026-ebf66a5321

Debian 12 · knot-resolver · NOT AFFECTED

Debian 13 · knot-resolver · NOT AFFECTED

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: venglin/knot-doq (0 stars)
Write-up: openwall.com/lists/oss-security/2026/07/23/6

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-66374?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Is CVE-2026-66374 being exploited?

CVE-2026-66374 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-66374 affect?

CVE-2026-66374 affects affected software. Severity is high (CVSS 8.1). Knot Resolver before 6.4.1 allows remote code execution via a heap-based buffer overflow in the DoQ (DNS-over-QUIC) receive path.

How urgent is CVE-2026-66374?

Priority 49/100. High severity; CISA SSVC: public proof of concept; Remotely exploitable, no login, no user action

References

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