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RUSTSEC-2026-0208

HighCVSS 8.2 / 10
Published May 21, 2026·Last modified Jul 17, 2026
Affected Components(0)

No affected components available

Description

The AVX2-optimized implementation of SHAKE-256 intended for use in ML-KEM and ML-DSA would panic if the length of the output buffers was greater than 32 and not a multiple of 8, due to an out-of-bounds indexing operation.

Impact

This bug impacts users on AVX2 platforms that use the libcrux_sha3::avx2::x4::shake256 API outside of ML-KEM or ML-DSA with output buffers of length > 32 and not divisible by 8. It does not impact the use in ML-KEM or ML-DSA because there output buffer lengths are always divisible by 8.

Mitigation

Starting from version 0.0.10, the AVX2-optimized SHAKE-256 will no longer panic on output buffer lengths > 32 that are not divisible by 8.

Risk Scores
Base Score
8.2

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability.

Threat Intelligence
4.6

Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.

EPSS
N/A

Probability that this vulnerability will be exploited in the wild within the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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