cvedb.io
CVE-2026-6331
HIGH · CVSS 7.5
EPSS exploitation probability: 0%
Published 2026-06-25T22:17:03.010 · Last modified 2026-06-27T19:48:56.343

Summary

HMAC zero-length tag forgery in EVP_DigestVerifyFinal, where a zero-length tag could be accepted as valid during HMAC verification. In the OpenSSL-compatibility HMAC verify path the supplied signature length was only checked as not exceeding the MAC length, so a zero-length or otherwise truncated tag could pass verification. The fix requires the supplied tag length to exactly equal the MAC length and rejects a zero-length MAC, so a forged short or empty tag is no longer accepted.

Affected products

wolfssl — wolfssl

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.