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VULNERABILITIES

CVE-2026-39155 Details

ANALYZED

This CVE record has been analyzed and enriched by NVDAPI.com as an independent party.

Description

Knot DNS before 3.4.10 and 3.5.x before 3.5.4 contains a vulnerability in mod-onlinesign where the next NSEC owner name can be computed incorrectly. This can create an overly broad authenticated denial interval, allowing downstream validating resolvers using aggressive negative caching to synthesize negative answers for legitimate names and causing resolver-side denial of service.

Metrics

CVSS 3.x Severity and Vector Strings:

NDDVolerionCVSS-B:4 MEDIUMVector:CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:L
CNA: CISA-ADPCVSS-B:6.5 MEDIUMVector:CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References to Advisories, Solutions, and Tools

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URLSource(s)Tag(s)
https://www.knot-dns.cz/2026-04-01-version-3410.html [email protected]Release NotesVendor
https://www.knot-dns.cz/2026-04-02-version-354.html [email protected]Release NotesVendor

Weakness Enumeration

CWE-IDCWE NameSource
CWE-345Insufficient Verification of Data AuthenticityCISA-ADP

Affected Products

ProductVersions
Knot DNS
< 3.4.10 (semver)
>= 3.5, < 3.5.4

CPE

  • cpe:2.3:a:knot-dns:knot_dns:*:*:*:*:*:*:*:*

Remediation

  • Upgrade: 3.4.10moderate effort
  • Upgrade: 3.5.4moderate effort

Change History

2 change records found show changes

QUICK INFO

CVE Dictionary Entry:
CVE-2026-39155
NVD Published Date:
Jul 23, 2026
NVD Last Modified:
Jul 30, 2026
Source:
[email protected]
CVE-2026-39155 Details - Not Deferred