{"containers":{"adp":[{"metrics":[{"other":{"content":{"id":"CVE-2026-55962","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","timestamp":"2026-06-26T10:30:28.816026Z","version":"2.0.3"},"type":"ssvc"}}],"providerMetadata":{"dateUpdated":"2026-06-26T10:31:12.017Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"title":"CISA ADP Vulnrichment"}],"cna":{"affected":[{"collectionURL":"https://github.com/wolfSSL/wolfssl","defaultStatus":"unaffected","product":"wolfSSL","vendor":"wolfSSL","versions":[{"lessThanOrEqual":"5.9.1","status":"affected","version":"5.5.4","versionType":"semver"}]}],"credits":[{"lang":"en","type":"finder","value":"NVIDIA Project Vanessa"}],"descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<p>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.</p>"}],"value":"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."}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":6,"baseSeverity":"MEDIUM","exploitMaturity":"NOT_DEFINED","privilegesRequired":"LOW","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"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","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-287","description":"CWE-287 Improper Authentication","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-06-25T21:12:38.074Z","orgId":"50d2cd11-d01a-48ed-9441-5bfce9d63b27","shortName":"wolfSSL"},"references":[{"tags":["patch"],"url":"https://github.com/wolfSSL/wolfssl/pull/10702"},{"url":"https://www.wolfssl.com/docs/security-vulnerabilities/"}],"source":{"discovery":"UNKNOWN"},"title":"TLS 1.3 post-handshake authentication: server accepts Finished without client Certificate/CertificateVerify","x_generator":{"engine":"Vulnogram 1.0.2"}}},"cveMetadata":{"assignerOrgId":"50d2cd11-d01a-48ed-9441-5bfce9d63b27","assignerShortName":"wolfSSL","cveId":"CVE-2026-55962","datePublished":"2026-06-25T21:12:38.074Z","dateReserved":"2026-06-17T22:10:55.453Z","dateUpdated":"2026-06-26T10:31:12.017Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"}