CVE-2026-6330

The ML-KEM ARM64 NEON ciphertext comparison only compares half of the input, breaking the Fujisaki-Okamoto transform's implicit rejection and weakening IND-CCA2 security on that code path. The constant-time comparison effectively ignored part of the re-encrypted ciphertext, so a decapsulating party could fail to detect a manipulated ciphertext and proceed without the standard's required implicit rejection.

Affected products

Ml-Kem

Wolfssl

< 5.9.2

CVSS 3.1

6.5 MEDIUM

EPSS

0.2% (6th percentile)

Weakness

CWE-327

NVD status

Analyzed

Published

2026-06-25