{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-91768","assignerOrgId":"dd77f84a-d19a-4638-8c3d-a322d820ed2b","state":"PUBLISHED","assignerShortName":"php","dateReserved":"2026-09-15T00:42:30.045Z","datePublished":"2026-09-25T21:07:30.950Z","dateUpdated":"2026-09-25T21:07:30.950Z"},"containers":{"cna":{"providerMetadata":{"orgId":"dd77f84a-d19a-4638-8c3d-a322d820ed2b","shortName":"php","dateUpdated":"2026-09-25T21:07:30.950Z"},"title":"IPv6 ACL bypass in FastCGI listen.allowed_clients due to partial address comparison (memcmp 12 bytes)","problemTypes":[{"descriptions":[{"lang":"en","cweId":"CWE-1023","description":"CWE-1023","type":"CWE"}]}],"impacts":[{"capecId":"CAPEC-1","descriptions":[{"lang":"en","value":"CAPEC-1 Accessing Functionality Not Properly Constrained by ACLs"}]}],"affected":[{"vendor":"PHP Group","product":"PHP","packageName":"PHP-FPM","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":"The IPv6 branch of the FastCGI client access check compares only the first 12 bytes of a 16-byte IPv6 address, so listen.allowed_clients matches on a /96 prefix instead of the exact address. An attacker who can source an address sharing the first 96 bits with an allowed one passes the check and reaches the FastCGI endpoint.","supportingMedia":[{"type":"text/html","base64":false,"value":"<p>The IPv6 branch of the FastCGI client access check compares only the first 12 bytes of a 16-byte IPv6 address, so <code>listen.allowed_clients</code> matches on a /96 prefix instead of the exact address. An attacker who can source an address sharing the first 96 bits with an allowed one passes the check and reaches the FastCGI endpoint.</p>"}]}],"references":[{"url":"https://github.com/php/php-src/security/advisories/GHSA-62xp-839h-2637","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":"HIGH","integrityImpact":"NONE","availabilityImpact":"NONE","baseSeverity":"MEDIUM","baseScore":6.5,"vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"}}],"credits":[{"lang":"en","value":"@l8BL (GitHub)","type":"reporter"},{"lang":"en","value":"@OSTIF-Derek (GitHub)","type":"reporter"},{"lang":"en","value":"Ilia Alshanetsky","type":"reporter"},{"lang":"en","value":"Alexandre Daubois","type":"remediation developer"},{"lang":"en","value":"Arnaud Le Blanc","type":"remediation reviewer"},{"lang":"en","value":"Jakub Zelenka","type":"remediation reviewer"}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"Vulnogram 1.0.5"}}}}