knot-resolver vulnerabilities

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.

CVE-2023-50868

The Closest Encloser Proof aspect of the DNS protocol (in RFC 5155 when RFC 9276 guidance is skipped) allows remote attackers to cause a denial of service (CPU consumption for SHA-1 computations) via DNSSEC responses in a random subdomain attack, aka the "NSEC3" issue. The RFC 5155 specification implies that an algorithm must perform thousands of iterations of a hash function in certain situations.

CVE-2023-50387

Certain DNSSEC aspects of the DNS protocol (in RFC 4033, 4034, 4035, 6840, and related RFCs) allow remote attackers to cause a denial of service (CPU consumption) via one or more DNSSEC responses, aka the "KeyTrap" issue. One of the concerns is that, when there is a zone with many DNSKEY and RRSIG records, the protocol specification implies that an algorithm must evaluate all combinations of DNSKEY and RRSIG records.

CVE-2023-46317

Knot Resolver before 5.7.0 performs many TCP reconnections upon receiving certain nonsensical responses from servers.

CVE-2023-26249

Knot Resolver before 5.6.0 enables attackers to consume its resources, launching amplification attacks and potentially causing a denial of service. Specifically, a single client query may lead to a hundred TCP connection attempts if a DNS server closes connections without providing a response.

CVE-2022-40188

Knot Resolver before 5.5.3 allows remote attackers to cause a denial of service (CPU consumption) because of algorithmic complexity. During an attack, an authoritative server must return large NS sets or address sets.

• Update to 5.4.4-1ubuntu0.1~esm1

CVE-2022-32983

Knot Resolver through 5.5.1 may allow DNS cache poisoning when there is an attempt to limit forwarding actions by filters.