CVE-2026-6330 ML-KEM ARM64 NEON ciphertext comparison only compares half of the input
A flaw in wolfSSL's ARM64 NEON implementation allows attackers to bypass IND-CCA2 security checks by manipulating ciphertexts undetected.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-6330?
CVE-2026-6330 is a medium-severity vulnerability in Wolfssl Wolfssl, published on 25 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-327
Which versions are affected by CVE-2026-6330?
It affects 1 product.
Products include Wolfssl Wolfssl.
How do I fix CVE-2026-6330?
Apply the vendor's patch.
Is CVE-2026-6330 being exploited?
There is no known exploitation of CVE-2026-6330 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in Wolfssl Wolfssl
Sources
Also known as DEBIAN-CVE-2026-6330, GHSA-89v8-3927-wfcg, JLSEC-2026-748, UBUNTU-CVE-2026-6330.