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TI-2023-11416 Aliases CVE-2023-26249GHSA-38wr-pjxc-vgf7

Knot Resolver before 5.6.0 enables attackers to consume its resources, launching…

Priority MEDIUM 40CWE-770Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-770.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00708 53rd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:nic:knot_resolver:*:*:*:*:*:*:*:*before 5.6.0VulnerableCZ.NIC
  • cpe:2.3:a:nic:knot_resolver:*:*:*:*:*:*:*:* Versions before 5.6.0 Vulnerable ·CZ.NIC

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2023-26249
  2. 2026-10-03 Alias added: GHSA-38wr-pjxc-vgf7

References

Advisory 1

  • TI-2023-27571 Certain DNSSEC aspects of the DNS protocol (in RFC 4033, 4034, 4035, 6840, and related… CVSS 3.1HIGH 7.5
  • TI-2020-10072 Knot Resolver before 5.1.1 allows traffic amplification via a crafted DNS answer from an… CVSS 3.1HIGH 7.5
  • TI-2022-19055 Knot Resolver before 5.5.3 allows remote attackers to cause a denial of service (CPU… CVSS 3.1HIGH 7.5
  • TI-2023-24930 Knot Resolver before 5.7.0 performs many TCP reconnections upon receiving certain nonsensical responses from servers. CVSS 3.1HIGH 7.5
  • TI-2019-13943 knot-resolver before version 4.3.0 is vulnerable to denial of service through high CPU… CVSS 3.1HIGH 7.5
  • TI-2019-07512 Improper input validation in CZ.NIC knot-resolver CVSS 3.1HIGH 7.5
See all 13 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences