Remote Code Execution Vulnerability in Knot Resolver by CZ.NIC
CVE-2026-66374

8.1HIGH

Key Information:

Vendor

Nic

Status
Knot Resolver
Vendor
CVE Published:
25 July 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-66374?

A vulnerability in Knot Resolver allows for remote code execution due to a heap-based buffer overflow in the DNS-over-QUIC (DoQ) receive path. This flaw could potentially be exploited by an attacker to execute arbitrary code on the affected system after sending specially crafted packets, posing significant security risks.

Affected Version(s)

Knot Resolver 0 < 6.4.1

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

knot-doq
Created by venglin

References

https://openwall.com/lists/oss-security/2026/07/23/6
https://github.com/venglin/knot-doq

CVSS V3.1

Score:
8.1
Severity:
HIGH
Confidentiality:
Low
Integrity:
High
Availability:
Low
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
None
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

.