Improper Verification of Cryptographic Signature in wolfSSL - CVE-2026-6331
Published: July 1, 2026
Vulnerability identifier: #VU136649
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-6331
CWE-ID: CWE-347
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: wolfSSL
Affected software:
wolfSSL
wolfSSL
Detailed vulnerability description
The vulnerability allows a remote attacker to forge HMAC verification results.
The vulnerability exists due to improper authentication in EVP_DigestVerifyFinal when verifying HMAC tags. A remote attacker can supply a zero-length tag to forge HMAC verification results.
How to mitigate CVE-2026-6331
Install security update from vendor's website.