Reported

March 4, 2026

Issued

March 24, 2026

Package

libcrux-sha3 (crates.io)

Type

Vulnerability

References

• https://github.com/cryspen/libcrux/pull/1352

Patched

• >=0.0.8

Affected Functions

Version

libcrux_sha3::portable::incremental::Shake128Xof::squeeze

• <=0.0.7

libcrux_sha3::portable::incremental::Shake256Xof::squeeze

• <=0.0.7

Description

The incremental squeeze functions in the portable SHAKE XOF API, when attempting to squeeze more than RATE (168 for SHAKE128, 136 for SHAKE256) bytes, performed an additional permutation of the state before producing the first output block, thus discarding the first block of RATE bytes of valid XOF output.

Impact

This bug impacts users that rely on this XOF API to squeeze more than RATE bytes. It does not impact the use of libcrux-sha3 in libcrux-ml-kem or libcrux-ml-dsa.

Mitigation

Starting from version 0.0.8 the squeeze functions correctly output all blocks including the first block.

Advisory available under CC0-1.0 license.