{"id":"CVE-2026-8417","aliases":["GHSA-jr5g-qv3g-rxxx"],"url":"https://o3.security/vulnerability/CVE-2026-8417","summary":"Concrete CMS 9.5.0 and below is vulnerable to CSRF in do_update() in the package update controller","details":"Concrete CMS 9.5.0 and below does not validate a CSRF token before processing requests to /dashboard/extend/update/do_update/<pkgHandle>. The do_update() method in concrete/controllers/single_page/dashboard/extend/update.php checks only canInstallPackages() before executing upgradeCoreData() and upgrade() on the named package's controller. Because the endpoint is a state-changing GET route with no token enforcement, an attacker can force an authenticated administrator to trigger a package upgrade via a single cross-site navigation.In order to be vulnerable, the victim must be passing canInstallPackages() and and a target package must already be already installed. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 7.5 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks  https://github.com/maru1009  for reporting.","published":"2026-05-21T20:19:42.643Z","modified":"2026-08-12T03:51:45.322128961Z","cvss":null,"epss":{"score":0.00122,"percentile":0.02325,"asOf":"2026-08-18"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Packagist","name":"concrete5/concrete5","fixedVersion":"9.5.1"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/8xxx/CVE-2026-8417.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-8417"},{"type":"PACKAGE","url":"https://github.com/concretecms/concretecms"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:45.322128961Z"}}