How severe is GHSA-6w6g-hm98-mhgm?

No CVSS score has been assigned to GHSA-6w6g-hm98-mhgm yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-6w6g-hm98-mhgm?

GHSA-6w6g-hm98-mhgm affects the following packages: hickory-resolver (crates.io). Ecosystems affected: crates.io.

How do I fix GHSA-6w6g-hm98-mhgm?

Update hickory-resolver to 0.26.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6w6g-hm98-mhgm is resolved across your whole dependency graph.

How do I detect GHSA-6w6g-hm98-mhgm in my crates.io dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for hickory-resolver, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-6w6g-hm98-mhgm 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.

Is GHSA-6w6g-hm98-mhgm actively exploited in the wild?

No public exploit code has been indexed for GHSA-6w6g-hm98-mhgm 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-6w6g-hm98-mhgm published, and has it been updated?

GHSA-6w6g-hm98-mhgm was published on October 5, 2026 and was last updated on October 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

Not in CISA KEV

hickory-resolver: Unbounded TC-retry loop in `NameServerPool::try_send` (resource-exhaustion DoS)GHSA-6w6g-hm98-mhgm

Fix: hickory-dns/hickory-dns#3871

GHSA-6w6g-hm98-mhgm is a security vulnerability in hickory-resolver. A fix is available for hickory-resolver — see the affected versions and patch details below.

Published

Oct 5, 2026

Updated

Oct 5, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 5, 2026 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

🦀hickory-resolver

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

When the hickory-resolver name server pool implementation receives an upstream response with the TC (truncated) header bit set, it re-queues the request to the same nameserver to retry with UDP transport disabled. However, the retry arm never inspects the transport that just answered and carries no iteration counter. An authoritative server that sets TC=1 on every available transport keeps the resolver spinning on one persistent TCP connection until the 5s per-request wall-clock deadline expires.

Reporter

Qifan Zhang, Palo Alto Networks

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🦀crates.io	`hickory-resolver`	≥ 0.26.0-beta.1&&< 0.26.2	0.26.2`cargo update -p hickory-resolver --precise 0.26.2`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for hickory-resolver, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update hickory-resolver to 0.26.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6w6g-hm98-mhgm 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.

Frequently Asked Questions

When the `hickory-resolver` name server pool implementation receives an upstream response with the TC (truncated) header bit set, it re-queues the request to the same nameserver to retry with UDP transport disabled. However, the retry arm never inspects the transport that just answered and carries no iteration counter. An authoritative server that sets `TC=1` on **every** available transport keeps the resolver spinning on one persistent TCP connection until the 5s per-request wall-clock deadline expires. ### Reporter Qifan Zhang, Palo Alto Networks

O3 Security · Impact-Aware SCA

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