CVE-2026-55962
As of 2026-06-26, CVE-2026-55962 is a CVSS 6.5 (MEDIUM-severity) vulnerability. EPSS exploitation probability 0.2%. Threadlinqs Intelligence tracks 0 threats exploiting it.
Last updated: 2026-06-26
TLS 1.3 post-handshake authentication (PHA) issue where a server could accept a client's Finished message without the client having sent a Certificate and CertificateVerify. The post-handshake-auth exemption that allows an empty/absent peer certificate was only intended for the initial handshake, but it was also being applied while a post-handshake CertificateRequest was still outstanding. The check is now scoped to the initial handshake only: on the server, once a post-handshake CertificateRequest has been sent (certReqCtx is set), a peer certificate and a valid CertificateVerify are required again before the Finished is accepted, with empty-certificate handling following the configured verify mode (FAIL_IF_NO_PEER_CERT) just as during first-handshake client authentication. Only affects TLS 1.3 servers built with post-handshake authentication support (WOLFSSL_POST_HANDSHAKE_AUTH / --enable-postauth, included in --enable-all) that enable WOLFSSL_VERIFY_POST_HANDSHAKE and request a client certificate after the handshake via wolfSSL_request_certificate(). Clients, and servers that do not use post-handshake authentication, are unaffected.
CVSS v3 vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Weaknesses (CWE)
CWE-287
References
← all vulnerabilities · Markdown version · Threadlinqs Intelligence
Enriched from CVE.org, NVD (this product uses the NVD API but is not endorsed or certified by the NVD), FIRST EPSS, CISA KEV, and GitHub Security Advisories.