CVE-2026-6331 Affecting wolfssl package, versions <5.9.2-1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-DEBIANUNSTABLE-WOLFSSL-17547481
- published26 Jun 2026
- disclosed25 Jun 2026
Introduced: 25 Jun 2026
NewCVE-2026-6331 (opens in a new tab)How to fix?
Upgrade Debian:unstable wolfssl to version 5.9.2-1 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream wolfssl package and not the wolfssl package as distributed by Debian.
See How to fix? for Debian:unstable relevant fixed versions and status.
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.