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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-83hf-93m4-rgwq can be triaged on real exposure rather than presence alone.

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.

What is the EPSS score for GHSA-83hf-93m4-rgwq?

GHSA-83hf-93m4-rgwq has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 6th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-83hf-93m4-rgwq?

GHSA-83hf-93m4-rgwq is classified as CWE-706 (CWE-706). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

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 July 8, 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

Not in CISA KEV

GHSA-83hf-93m4-rgwq — hickory-recursor

GHSA-83hf-93m4-rgwq is a CWE-706 vulnerability in hickory-recursor. A fix is available for hickory-recursor — see the affected versions and patch details below.

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

Also known asCVE-2026-42254

Published

Apr 30, 2026

Updated

Jul 8, 2026

Affected

2 pkgs

Patched

1 / 2

Exploits

None indexed

Exploitation data as of Sep 19, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-83hf-93m4-rgwq.

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs6th percentile — riskier than 6% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

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`cargo update -p hickory-recursor --precise 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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-83hf-93m4-rgwq can be triaged on real exposure rather than presence alone.

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 Security finds GHSA-83hf-93m4-rgwq across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works