Medium severity · published Jun 25, 2026
CVE-2026-6330
ML-KEM ARM64 NEON ciphertext comparison only compares half of the input
6.5
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 6% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
WO
wolfSSL · wolfSSL
5.7.4 through 5.9.1 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-6330
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-6330
Issue Tracking
https://github.com/wolfSSL/wolfssl/pull/10192
Vendor Advisory
https://www.wolfssl.com/docs/security-vulnerabilities/
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