{"id":81087,"date":"2026-06-26T00:42:38","date_gmt":"2026-06-25T21:12:38","guid":{"rendered":"https:\/\/afaghhosting.net\/blog\/cve-2026-55962-tls-1-3-post-handshake-authentication-server-accepts-finished-without-client-certificate-certificateverify\/"},"modified":"2026-06-26T00:42:38","modified_gmt":"2026-06-25T21:12:38","slug":"cve-2026-55962-tls-1-3-post-handshake-authentication-server-accepts-finished-without-client-certificate-certificateverify","status":"publish","type":"post","link":"https:\/\/afaghhosting.net\/blog\/cve-2026-55962-tls-1-3-post-handshake-authentication-server-accepts-finished-without-client-certificate-certificateverify\/","title":{"rendered":"CVE-2026-55962 &#8211; TLS 1.3 post-handshake authentication: server accepts Finished without client Certificate\/CertificateVerify"},"content":{"rendered":"<p>CVE ID :CVE-2026-55962<\/p>\n<p>  Published : June 25, 2026, 9:12 p.m. | 32\u00a0minutes ago<\/p>\n<p>  Description :TLS 1.3 post-handshake authentication (PHA) issue where a server could accept a client&#8217;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 \/ &#8211;enable-postauth, included in &#8211;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.<\/p>\n<p>  Severity: 6.0 | MEDIUM<\/p>\n<p>  Visit the link for more details, such as CVSS details, affected products, timeline, and more&#8230;\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"<p>CVE ID :CVE-2026-55962 Published : June 25, 2026, 9:12 p.m. | 32\u00a0minutes ago Description :TLS 1.3 post-handshake authentication (PHA) issue where a server could accept a client&#8217;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 &hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[26],"tags":[],"class_list":["post-81087","post","type-post","status-publish","format-standard","hentry","category-vulnerability"],"_links":{"self":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/81087","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/comments?post=81087"}],"version-history":[{"count":0,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/81087\/revisions"}],"wp:attachment":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/media?parent=81087"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/categories?post=81087"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/tags?post=81087"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}