What is GHSA-fhvh-vw7h-9xf3?

GHSA-fhvh-vw7h-9xf3 is a security advisory published by GitHub Security Advisories with High severity. libcrux-ml-dsa: Signature Verification on AVX2 Platforms Mishandles Edge Case

Why does GHSA-fhvh-vw7h-9xf3 have no CVE ID yet?

GitHub Security Advisories published this advisory directly to customers before NVD assigned a CVE ID. This is the embargo-window disclosure pattern — vendors notify customers on day 0; NVD's public record follows days to weeks later.

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

GHSA-fhvh-vw7h-9xf3 affects 1 product, including: rust/libcrux-ml-dsa:\u003c 0.0.9.

GHSA-fhvh-vw7h-9xf3HighDisclosed before NVD

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

Vendor

GitHub Security Advisories

Published

May 19, 2026

Last Modified

May 19, 2026

📋 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 products1

rust/libcrux-ml-dsa:< 0.0.9

🔗 References (5)

https://github.com/C2SP/wycheproof/pull/234
https://github.com/cryspen/libcrux/pull/1398
https://github.com/tink-crypto/tink-go/pull/48
https://rustsec.org/advisories/RUSTSEC-2026-0125.html
https://github.com/advisories/GHSA-fhvh-vw7h-9xf3