{"id":"CVE-2026-111815","published":"2026-10-21T20:17:23.330","lastModified":"2026-10-23T12:18:09.333","description":"Apache Traffic Server can resume a TLS session across SNI virtual hosts without re-verifying a client certificate required by the resumed host's verify_client STRICT policy.\n\n\n\nThis issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0.\n\n\n\nUsers are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.","cvssScore":10,"cvssSeverity":"CRITICAL","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N","cwes":["CWE-295"],"vendors":[],"products":[],"references":[{"url":"https://lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb12z4s4kc","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":{"summary":"Apache Traffic Server incorrectly allows TLS session resumption across SNI virtual hosts without re-checking client certificate requirements, meaning a client that previously connected to one host (without a required cert) can reuse that session on another host that mandates STRICT client verification.","exploitability":"Remote exploitation is trivial for an attacker who has already established a TLS session with a non-strict host and then targets a strict host using the same SNI name or overlapping session cache; no user interaction or prior authentication is needed.","blast_radius":"An attacker can bypass client certificate enforcement on strict virtual hosts, gaining unauthorized access to resources protected by mutual TLS, potentially leading to data exfiltration or privilege escalation within the TLS-protected scope.","remediation":"Upgrade to Apache Traffic Server version 9.2.16, 10.1.5, or 10.2.1, which explicitly enforce client certificate verification on every TLS handshake, including during session resumption.","detection":"Log entries showing successful TLS handshakes with resumed sessions on hosts configured with verify_client=STRICT, especially when the original handshake lacked a client certificate, may indicate exploitation; inspect ssl_handshake logs for mismatched certificate presence across resumptions.","tags":["tls-misconfig","sni-bypass","mtls-bypass","session-resumption","auth-bypass"],"model":"garnet-coder","analyzedAt":"2026-10-24T08:45:44.929Z"}}