High severity · published Jul 25, 2026
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
8.1
CVSS
0.6%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:L
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
High
Availability
Low
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 50% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KR
Knot Resolver · nic
before 6.4.1 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-66374
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-66374
github.com
https://github.com/venglin/knot-doq
openwall.com
https://openwall.com/lists/oss-security/2026/07/23/6
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