{"cve":{"cve_id":"CVE-2026-55962","is_kev":false,"kev_date_added":null,"kev_vendor_project":null,"kev_product":null,"kev_vulnerability_name":null,"kev_short_description":null,"kev_required_action":null,"kev_due_date":null,"kev_known_ransomware":null,"kev_notes":null,"kev_cwes":null,"epss_score":null,"epss_percentile":null,"epss_as_of":null,"description":"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.","published_at":"2026-06-25T21:12:38.074000Z","last_modified_at":null,"cvss_v3_score":null,"cvss_v3_vector":null,"cvss_v3_severity":null,"cvss_v4_score":6.0,"cvss_v4_vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","cvss_v4_severity":"MEDIUM","ssvc_decision":null,"ssvc_exploitation":null,"ssvc_automatable":null,"ssvc_technical_impact":null,"cwes":["CWE-287"],"nvd_references":["https://github.com/wolfSSL/wolfssl/pull/10702","https://www.wolfssl.com/docs/security-vulnerabilities/"],"vuln_status":null,"trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-06-28T17:55:37.240342Z","updated_at":"2026-06-28T23:30:56.588703Z"},"effective_severity":"MEDIUM","badges":[],"impact_analysis":[],"cvss_v3_decoded":{"version":null,"metrics":[]},"cvss_v4_decoded":{"version":"4.0","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"AT","name":"Attack Requirements","value":"P","value_label":"Present"},{"metric":"PR","name":"Privileges Required","value":"L","value_label":"Low"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"VC","name":"Confidentiality (Vulnerable System)","value":"N","value_label":"None"},{"metric":"VI","name":"Integrity (Vulnerable System)","value":"H","value_label":"High"},{"metric":"VA","name":"Availability (Vulnerable System)","value":"N","value_label":"None"},{"metric":"SC","name":"Confidentiality (Subsequent System)","value":"N","value_label":"None"},{"metric":"SI","name":"Integrity (Subsequent System)","value":"N","value_label":"None"},{"metric":"SA","name":"Availability (Subsequent System)","value":"N","value_label":"None"}]},"affected":[{"vendor_slug":"wolfssl","vendor_name":"wolfSSL","product_slug":"wolfssl","product_name":"wolfSSL","version_start":"5.5.4","version_start_inclusive":true,"version_end":"5.9.1","version_end_inclusive":true,"cpe23_uri":"cve5:wolfssl:wolfssl:5.5.4:5.9.1"}],"exploit_refs":[],"news":[],"references":[{"url":"https://github.com/wolfSSL/wolfssl/pull/10702","source_type":"PATCH","tags":["patch"]},{"url":"https://www.wolfssl.com/docs/security-vulnerabilities/","source_type":"MISC","tags":[]}],"timeline":[{"type":"published","at":"2026-06-25T21:12:38.074000Z","label":"CVE published","source":null}]}