Vulnerability · Published Jul 25, 2026 · Assigned by mitre
CVE-2026-66374
High 8.1
In plain English
A high-severity security flaw in Knot Resolver from nic. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 50% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)8.1High
Exploit odds (30 days)0.6%top 49.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack tooling1Public PoC
Official description
Knot Resolver before 6.4.1 allows remote code execution via a heap-based buffer overflow in the DoQ (DNS-over-QUIC) receive path.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:14 | knot-resolver | 6.4.1-1 | DEBIAN-CVE-2026-66374 |
| Ubuntu:24.04:LTS | knot-resolver | no fix listed | UBUNTU-CVE-2026-66374 |
| Ubuntu:26.04:LTS | knot-resolver | no fix listed | UBUNTU-CVE-2026-66374 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| nic | Knot Resolver | 0 – before 6.4.1 |
Weakness: CWE-1284 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:L