CVE catalog
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.
- Severity
- High · CVSS 8.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:L - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.62% · Oct 25, 2026
Knot Resolver before 6.4.1 allows remote code execution via a heap-based buffer overflow in the DoQ (DNS-over-QUIC) receive path.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | knot-resolver | sid | 6.5.0-2 | fixed |
| Debian | knot-resolver | forky | 6.4.2-1 | fixed |
| Debian | knot-resolver | trixie | 5.7.5-1 | not affected |
| Debian | knot-resolver | bookworm | 5.6.0-1+deb12u1 | not affected |
| Debian | knot-resolver | bookworm-security | 5.6.0-1+deb12u1 | not affected |
| Ubuntu | knot-resolver | pro | 5.3.1-1 | vulnerable |
| Ubuntu | knot-resolver | pro | 5.4.2-1 | vulnerable |
| Ubuntu | knot-resolver | pro | 5.4.3-1 | vulnerable |
| Ubuntu | knot-resolver | pro | 5.4.4-1 | vulnerable |
| Ubuntu | knot-resolver | pro | 5.4.4-1ubuntu0.1~esm1 | vulnerable |
| Ubuntu | knot-resolver | 20.04 | 3.2.1-3 | vulnerable |
| Ubuntu | knot-resolver | 20.04 | 3.2.1-3ubuntu1 | vulnerable |
| Ubuntu | knot-resolver | 20.04 | 3.2.1-3ubuntu2 | vulnerable |
| Ubuntu | knot-resolver | 20.04 | 3.2.1-3ubuntu2.1 | vulnerable |
| Ubuntu | knot-resolver | 20.04 | 3.2.1-3ubuntu2.2 | vulnerable |
| Ubuntu | knot-resolver | 24.04 | 5.6.0-1.1 | vulnerable |
| Ubuntu | knot-resolver | 24.04 | 5.7.0-1build1 | vulnerable |
| Ubuntu | knot-resolver | 24.04 | 5.7.1-1 | vulnerable |
| Ubuntu | knot-resolver | 24.04 | 5.7.2-1 | vulnerable |
| Ubuntu | knot-resolver | 26.04 | 5.7.5-1 | vulnerable |
| Ubuntu | knot-resolver | 26.04 | 6.0.15-4build1 | vulnerable |
| Ubuntu | knot-resolver | 26.04 | 6.0.17-1 | vulnerable |
| Ubuntu | knot-resolver | 26.04 | 6.2.0-2 | vulnerable |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | knot-resolver | source | sid | 6.4.1-1 | not yet assigned | Not reported | Not reported |
| Debian | knot-resolver | source | forky | 6.4.1-1 | not yet assigned | Not reported | Not reported |
| Debian | knot-resolver | source | trixie | Not affected | unimportant | Not reported | Not reported |
| Debian | knot-resolver | source | bookworm | Not affected | unimportant | Not reported | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [knot-resolver]Not affected
Details (4)
5.6.0-1+deb12u1· amd64 · bookwormNot affected
nvd · knot-resolver · debian · bookworm
5.6.0-1+deb12u1· arm64 · bookwormNot affected
nvd · knot-resolver · debian · bookworm
5.6.0-1+deb12u1· amd64 · bookworm-securityNot affected
nvd · knot-resolver · debian · bookworm
5.6.0-1+deb12u1· arm64 · bookworm-securityNot affected
nvd · knot-resolver · debian · bookworm
- [knot-resolver-doc]Not affected
Source package: [knot-resolver]
Details (4)
5.6.0-1+deb12u1· all · bookwormNot affected
nvd · knot-resolver · debian · bookworm
5.6.0-1+deb12u1· all · bookwormNot affected
nvd · knot-resolver · debian · bookworm
5.6.0-1+deb12u1· all · bookworm-securityNot affected
nvd · knot-resolver · debian · bookworm
5.6.0-1+deb12u1· all · bookworm-securityNot affected
nvd · knot-resolver · debian · bookworm
- [knot-resolver-module-http]Not affected
Source package: [knot-resolver]
Details (4)
5.6.0-1+deb12u1· amd64 · bookwormNot affected
nvd · knot-resolver · debian · bookworm
5.6.0-1+deb12u1· arm64 · bookwormNot affected
nvd · knot-resolver · debian · bookworm
5.6.0-1+deb12u1· amd64 · bookworm-securityNot affected
nvd · knot-resolver · debian · bookworm
5.6.0-1+deb12u1· arm64 · bookworm-securityNot affected
nvd · knot-resolver · debian · bookworm
Observed:
References
- [https://github.com/venglin/knot-doq]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-66374]
- [https://openwall.com/lists/oss-security/2026/07/23/6]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-66374]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2026-66374]
- [https://security-tracker.debian.org/tracker/CVE-2026-66374]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-66374.json]
[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]