{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-91769","assignerOrgId":"dd77f84a-d19a-4638-8c3d-a322d820ed2b","state":"PUBLISHED","assignerShortName":"php","dateReserved":"2026-09-15T00:44:10.816Z","datePublished":"2026-09-25T20:59:39.727Z","dateUpdated":"2026-09-25T20:59:39.727Z"},"containers":{"cna":{"providerMetadata":{"orgId":"dd77f84a-d19a-4638-8c3d-a322d820ed2b","shortName":"php","dateUpdated":"2026-09-25T20:59:39.727Z"},"title":"TLS Hostname Verification Falls Back to CN After SAN Mismatch","problemTypes":[{"descriptions":[{"lang":"en","cweId":"CWE-297","description":"CWE-297 Improper validation of certificate with host mismatch","type":"CWE"}]}],"impacts":[{"capecId":"CAPEC-94","descriptions":[{"lang":"en","value":"CAPEC-94"}]}],"affected":[{"vendor":"PHP Group","product":"PHP","packageName":"ext-openssl","versions":[{"status":"affected","version":"8.2.*","lessThan":"8.2.34","versionType":"semver"},{"status":"affected","version":"8.3.*","lessThan":"8.3.35","versionType":"semver"},{"status":"affected","version":"8.4.*","lessThan":"8.4.26","versionType":"semver"},{"status":"affected","version":"8.5.*","lessThan":"8.5.11","versionType":"semver"}],"defaultStatus":"unaffected"}],"descriptions":[{"lang":"en","value":"PHP's OpenSSL stream peer verification checks the certificate's subjectAltName entries first and, whenever no entry matches, falls back to the Common Name. RFC 6125 requires the CN to be ignored once the certificate presents any service identity, so a certificate carrying a non-matching DNS SAN was still accepted when its CN matched the requested peer_name. A certificate trusted by the client for one name can therefore be used to impersonate another.","supportingMedia":[{"type":"text/html","base64":false,"value":"<p>PHP's OpenSSL stream peer verification checks the certificate's subjectAltName entries first and, whenever no entry matches, falls back to the Common Name. RFC 6125 requires the CN to be ignored once the certificate presents any service identity, so a certificate carrying a non-matching DNS SAN was still accepted when its CN matched the requested <code>peer_name</code>. A certificate trusted by the client for one name can therefore be used to impersonate another.</p>"}]}],"references":[{"url":"https://github.com/php/php-src/security/advisories/GHSA-vvx9-73fr-5jjx","tags":["vendor-advisory"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"version":"3.1","attackVector":"ADJACENT_NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"NONE","availabilityImpact":"NONE","baseSeverity":"MEDIUM","baseScore":4.3,"vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"}}],"credits":[{"lang":"en","value":"Cantina (https://www.cantina.security/)","type":"reporter"},{"lang":"en","value":"David Korczynski","type":"reporter"},{"lang":"en","value":"Jakub Zelenka","type":"remediation developer"},{"lang":"en","value":"Arnaud Le Blanc","type":"remediation reviewer"},{"lang":"en","value":"Alexandre Daubois","type":"remediation reviewer"}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"Vulnogram 1.0.5"}}}}