GHSA-fhvh-vw7h-9xf3 libcrux-ml-dsa: Signature Verification on AVX2 Platforms Mishandles Edge Case
Attackers can bypass signature verification in ML-DSA libraries using AVX2 instructions by crafting invalid signatures, requiring an upgrade to fix.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is GHSA-fhvh-vw7h-9xf3?
GHSA-fhvh-vw7h-9xf3 is a vulnerability in libcrux-ml-dsa, published on 5 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by GHSA-fhvh-vw7h-9xf3?
3 open source packages ship an affected version, including libcrux-ml-dsa.
| Package | Affected | Fixed in |
|---|---|---|
libcrux-ml-dsa crates.io | All versions | 0.0.9 |
libcrux-ml-dsa crates.io | All versions | 0.0.9 |
libcrux-ml-dsa crates.io | From 0.0.0-0 | 0.0.9 |
How do I fix GHSA-fhvh-vw7h-9xf3?
Upgrade libcrux-ml-dsa to 0.0.9 or later.
Is GHSA-fhvh-vw7h-9xf3 being exploited?
There is no known exploitation of GHSA-fhvh-vw7h-9xf3 in the wild and no public exploit code.
Sources
Also known as RUSTSEC-2026-0125.