How severe is GHSA-83hf-93m4-rgwq?

No CVSS score has been assigned to GHSA-83hf-93m4-rgwq yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-83hf-93m4-rgwq?

GHSA-83hf-93m4-rgwq affects the following packages: hickory-recursor (crates.io), hickory-recursor (crates.io). Ecosystems affected: crates.io.

How do I fix GHSA-83hf-93m4-rgwq?

Update hickory-recursor to 0.26.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-83hf-93m4-rgwq is resolved across your whole dependency graph.

How do I detect GHSA-83hf-93m4-rgwq in my crates.io dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for hickory-recursor. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-83hf-93m4-rgwq if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-83hf-93m4-rgwq?

O3 pinpoints whether GHSA-83hf-93m4-rgwq is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-83hf-93m4-rgwq actively exploited in the wild?

No public exploit code has been indexed for GHSA-83hf-93m4-rgwq yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was GHSA-83hf-93m4-rgwq published, and has it been updated?

GHSA-83hf-93m4-rgwq was published on April 30, 2026 and was last updated on May 5, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🦀 crates.io

GHSA-83hf-93m4-rgwq

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

Published

Apr 30, 2026

Updated

May 5, 2026

Affected

2 pkgs

Patched

1 / 2

Exploits

None indexed

Blast Radius

2 pkgs affected

🦀hickory-recursor🦀hickory-recursor

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.

Description

Summary

The Hickory DNS project's experimental hickory-recursor crate's record cache (DnsLru) stores records from DNS responses keyed by each record's own (name, type), not by the query that triggered the response. cache_response() in crates/recursor/src/lib.rs chains ANSWER, AUTHORITY, and ADDITIONAL sections into one record iterator before insertion. The bailiwick filter it applies uses the zone context of the NS pool that serviced the lookup, not the zone being queried.

This creates a cross-zone poisoning path. When Hickory builds the NS pool for attacker.poc. it uses the parent poc. NS pool (ns.zone() = "poc."). If the poc. nameserver under the attacker's control includes in its response's AUTHORITY section a record for a sibling zone like victim.poc. NS ns.evil.poc., the bailiwick check is_subzone("poc.", "victim.poc.") passes (victim.poc. is a subdomain of poc.). The record is stored under (victim.poc., NS) in the shared cache.

Subsequently, any client querying a name in victim.poc. causes Hickory to build its NS pool from the poisoned cache entry, routing queries to the attacker's nameserver (ns.evil.poc.) rather than to the legitimate nameserver for victim.poc.. The legitimate NS for that zone receives zero queries.

This issue is fixed in hickory-resolver 0.26.0 with the recursor feature through an architectural change to response-level caching: responses are stored keyed by the originating query (name, type). A response to (attacker.poc. NS) is stored only under that key and cannot affect the (victim.poc., NS) cache entry.

Hickory DNS believes this issue has been present in all published versions of the experimental hickory-recursor crate, which has now been folded into the hickory-resolver crate under the non-default recursor feature flag. The hickory-recursor crate will not receive any updates going forward and all users should migrate to hickory-resolver with the recursor feature.

Users of the hickory-dns binary configured with the opt-in recursor feature and a configuration acting as a recursive resolver should update to 0.26.0+.

Reporter

Qifan Zhang, Palo Alto Networks

Affected Packages

2 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🦀crates.io	`hickory-recursor`	≥ 0.24.0&&< 0.26.0	0.26.0
🦀crates.io	`hickory-recursor`	all versions	No fix

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for hickory-recursor. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update hickory-recursor to 0.26.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-83hf-93m4-rgwq is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-83hf-93m4-rgwq is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-83hf-93m4-rgwq. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

# Summary The Hickory DNS project's experimental `hickory-recursor` crate's record cache (`DnsLru`) stores records from DNS responses keyed by each record's own (name, type), not by the query that triggered the response. `cache_response()` in `crates/recursor/src/lib.rs` chains `ANSWER`, `AUTHORITY`, and `ADDITIONAL` sections into one record iterator before insertion. The bailiwick filter it applies uses the zone context of the NS pool that serviced the lookup, not the zone being queried. This creates a cross-zone poisoning path. When Hickory builds the NS pool for `attacker.poc.` it uses th

O3 Security · Impact-Aware SCA

Is GHSA-83hf-93m4-rgwq in your dependencies?

O3 detects GHSA-83hf-93m4-rgwq across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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