The vulnerability is a logic flaw in wolfSSL 5.8.2 and earlier where the TLS 1.2 server state machine may accept the CertificateVerify message before receiving the ClientKeyExchange message. This incorrect sequence can allow an attacker to influence the handshake process, potentially enabling the attacker to authenticate as a client without performing the proper key exchange, or disrupt the handshake. The primary impact is the potential for authentication bypass, which could allow unauthorized access to services protected by TLS client authentication. The weakness is identified as CWE‑358.

Affected vendor wolfSSL, product wolfSSL. The vulnerability applies to wolfSSL versions 5.8.2 and earlier. Versions 5.8.4 and higher have the issue fixed; 5.9.0 adds additional hardening.

The CVSS score is 5.5, indicating moderate severity. EPSS data is not available, and the vulnerability is not listed in the CISA KEV catalog, suggesting no known widespread exploitation. The attack would require an attacker to initiate a TLS 1.2 connection to the vulnerable server, exploiting the state machine flaw during the handshake. No public exploit code has been released, and the vulnerability is likely exploitable only in environments that rely on wolfSSL for TLS client authentication.