{"id":"CVE-2026-91939","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-91939","generatedAt":"2026-09-20T13:18:40.118Z","title":"Cotonti 1.0.0 Comments plugin passes the ci GET parameter to unserialize() without allowed_classes restriction, allowing unauthenticated attackers to instantiate arbitrary PHP classes with attacker-controlled properties.","description":"Cotonti 1.0.0 Comments plugin passes the ci GET parameter to unserialize() without allowed_classes restriction, allowing unauthenticated attackers to instantiate arbitrary PHP classes with attacker-controlled properties. Attackers can exploit PHP object injection through crafted serialized payloads to trigger gadget chains and achieve database manipulation or code execution.","published":"2026-09-15T21:16:49.000Z","lastModified":"2026-09-16T20:21:01.000Z","status":"Deferred","sourceIdentifier":"disclosure@vulncheck.com","cvss":{"version":"4.0","score":9.3,"severity":"CRITICAL","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-502"],"affected":[],"epss":{"score":0.00594,"percentile":0.47052,"date":"2026-09-19","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.59%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/Cotonti/Cotonti","source":"disclosure@vulncheck.com"},{"url":"https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/comments.setup.php","source":"disclosure@vulncheck.com"},{"url":"https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/controllers/actions/DisplayAction.php","source":"disclosure@vulncheck.com"},{"url":"https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/inc/CommentsWidget.php","source":"disclosure@vulncheck.com"},{"url":"https://github.com/Cotonti/Cotonti/issues/1888","source":"disclosure@vulncheck.com"},{"url":"https://github.com/Cotonti/Cotonti/pull/1889","source":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/cotonti-1.0.0-comments-plugin-php-object-injection-via-ci-parameter","source":"disclosure@vulncheck.com"},{"url":"https://github.com/Cotonti/Cotonti/issues/1888","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-91939","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}