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VulnerabilityPublished

Hickory recursor: Hickory DNS's Record Cache Accepts AUTHORITY-Section NS from Sibling Zone via Parent-Pool

Affects hickory-recursorSource GCVE Database

0

CVSS 8.7 High : upgrade to 0.26.0 soon.

Data as of 27 Oct 2026, 00:27 UTC

CVSS 4.0 base score
8.7High
How severe the flaw is on the 0–10 CVSS scale.
Patch
Available – fixed in 0.26.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

What to do

Upgrade hickory-recursor to 0.26.0.

Affected software

ProductAffectedFixed in
crates.iohickory-recursorAffected
  • >=0.24.0 <0.26.0
Fixed in
  • 0.26.0
crates.iohickory-recursorAffected
  • =0.1
Fixed in–

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AI-suggested

Users should upgrade to hickory-resolver version 0.26.0 or later with the recursor feature enabled, as this version includes an architectural fix that keys cache entries by the original query, preventing cross-zone poisoning. The hickory-recursor crate will not receive further updates, so migration to hickory-resolver is recommended. No other mitigations are indicated by the vendor.

Description

The Hickory DNS project's experimental recursor crate has a vulnerability in its record cache that allows cross-zone DNS cache poisoning. The cache stores DNS records keyed by each record's own name and type rather than by the original query, enabling an attacker controlling a parent zone to inject NS records for sibling zones. This causes recursive queries for the sibling zone to be redirected to the attacker's nameserver. The issue is fixed in hickory-resolver 0.26.0 with a change to response-level caching keyed by the query. Users of affected versions should upgrade to 0.26.0 or later.

References

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