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GHSA-fhvh-vw7h-9xf3

Fix: C2SP/wycheproof#234

GHSA-fhvh-vw7h-9xf3 is a security vulnerability in libcrux-ml-dsa. O3 Security confirms whether GHSA-fhvh-vw7h-9xf3 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

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
EcosystemPackageVulnerable rangeFix
🦀crates.iolibcrux-ml-dsaall versions0.0.9

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for libcrux-ml-dsa. 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.

  2. 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.

  3. 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.

  4. How O3 protects you

    O3 pinpoints whether GHSA-fhvh-vw7h-9xf3 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-fhvh-vw7h-9xf3. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

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

Is GHSA-fhvh-vw7h-9xf3 in your dependencies?

O3 detects GHSA-fhvh-vw7h-9xf3 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.

GHSA-fhvh-vw7h-9xf3: libcrux-ml-dsa | O3 Security