CVE-2026-55961: wolfSSL

High severity, CVSS 7.5. EPSS: 0.1% chance of exploitation in the next 30 days.

wolfSSL_PKCS7_verify() returning success for a degenerate (certs-only) PKCS#7 object that contains no signer. Such an object has empty signerInfos, so the underlying signed-data verification succeeds without authenticating any content. The compatibility-layer verify path now rejects the object when no signer signature has actually been verified, so a PKCS#7 carrying no valid signature is no longer reported as verified. This is enforced regardless of the PKCS7_NOVERIFY flag, which only suppresses signer certificate chain validation and was never intended to waive the requirement that a signature exist. Only affects OpenSSL compatibility builds that call the PKCS7_verify() compatibility API on potentially degenerate PKCS#7 bundles.

Affected products

• wolfSSL wolfSSL: from 3.15.7, before 5.9.2 (fixed in 5.9.2)

Published 2026-06-25. Last modified 2026-06-26.