How severe is GHSA-fhvh-vw7h-9xf3?

No CVSS score has been assigned to GHSA-fhvh-vw7h-9xf3 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-fhvh-vw7h-9xf3?

GHSA-fhvh-vw7h-9xf3 affects the following packages: libcrux-ml-dsa (crates.io). Ecosystems affected: crates.io.

How do I fix GHSA-fhvh-vw7h-9xf3?

Update libcrux-ml-dsa to 0.0.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fhvh-vw7h-9xf3 is resolved across your whole dependency graph.

How do I detect GHSA-fhvh-vw7h-9xf3 in my crates.io dependencies?

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

How do I mitigate GHSA-fhvh-vw7h-9xf3 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-fhvh-vw7h-9xf3 actively exploited in the wild?

No public exploit code has been indexed for GHSA-fhvh-vw7h-9xf3 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-fhvh-vw7h-9xf3 published, and has it been updated?

GHSA-fhvh-vw7h-9xf3 was published on May 19, 2026 and was last updated on May 20, 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-fhvh-vw7h-9xf3 — libcrux-ml-dsa

Fix: C2SP/wycheproof#234

GHSA-fhvh-vw7h-9xf3 is a security vulnerability in libcrux-ml-dsa. A fix is available for libcrux-ml-dsa — see the affected versions and patch details below.

libcrux-ml-dsa: Signature Verification on AVX2 Platforms Mishandles Edge Case

Also known asRUSTSEC-2026-0125

Published

May 19, 2026

Updated

May 20, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of May 20, 2026 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

🦀libcrux-ml-dsa

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

The AVX2 implementation of ML-DSA verification incorrectly implemented the use_hint function, mishandling an edge case that should lead to signature rejection.

Impact

An attacker could make the ML-DSA verifier accept a crafted invalid signature under a maliciously generated verification key, if the AVX2 implementation is used.

Mitigation

From version 0.0.9 the edge case is handled correctly and invalid signatures are rejected.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🦀crates.io	`libcrux-ml-dsa`	all versions	0.0.9`cargo update -p libcrux-ml-dsa --precise 0.0.9`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for libcrux-ml-dsa, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update libcrux-ml-dsa to 0.0.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fhvh-vw7h-9xf3 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

The AVX2 implementation of ML-DSA verification incorrectly implemented the `use_hint` function, mishandling an edge case that should lead to signature rejection. ## Impact An attacker could make the ML-DSA verifier accept a crafted invalid signature under a maliciously generated verification key, if the AVX2 implementation is used. ## Mitigation From version `0.0.9` the edge case is handled correctly and invalid signatures are rejected.

O3 Security · Impact-Aware SCA

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