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Fencer Intel
medium 5.3

CVE-2026-123581 json

Hickory DNS through 0.26.0-alpha.1 DNSSEC Validation Bypass via Unrelated RRset

published 2mo ago modified yesterday also EUVD-2026-119340 , GHSA-929p-gjf6-5hqj

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository hickory-dns/hickory-dns. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 2%
public exploits
0
none known

Summary

Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain a DNSSEC validation flaw that accepts a response as a positive answer when any valid RRset appears in the answer section, without checking that the RRset is responsive to the query. Attackers can supply signed but unrelated RRsets so that responses lacking matching records are validated as positive answers instead of as no-data responses.

Patch / fix

  • hickory-dns hickory-dns 0.26.2
  • rust-hickory-net Debian 14 0.26.3-1

debian advisories DEBIAN-CVE-2026-123581

Is CVE-2026-123581 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
yesterday

Exploit prediction

0.13% chance of exploitation in the next 30 days, higher than 2% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 4.0 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
CNA 4.0 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • hickory-dns hickory-dns

Classification

Weakness
  • CWE-345 Insufficient Verification of Data Authenticity

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of hickory-dns/hickory-dns published their own advisory on GitHub. Reviewed sources take precedence over it.