{"id":"CVE-2026-3240","aliases":["EUVD-2026-9358","GHSA-45fj-fvmm-xcc5"],"status":"published","title":"Concrete CMS below 9.4.8 is vulnerable to Stored XSS via Legacy form","description":"In Concrete CMS below version 9.4.8, a user with permission to edit a page with element Legacy form can perform a stored XSS attack towards high-privilege accounts via the Question field. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 4.8 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N Thanks minhnn42, namdi and quanlna2 from VCSLab-Viettel Cyber Security for reporting.","severity":{"version":"4.0","score":4.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00242,"percentile":0.15518,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-79"],"published":"2026-03-04T02:15:53Z","modified":"2026-10-28T02:31:11Z","fixes":[{"ecosystem":"Packagist","package":"concrete5/concrete5","fixed_in":["9.4.8"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"Packagist","package":"concrete5/concrete5","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"9.4.8"}]}]},{"source":"osv","ecosystem":"Packagist","package":"concrete5/concrete5","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"9.4.8"}]}],"versions":["8.0","8.0.1","8.0.2","8.0.3","8.1.0","8.2.0","8.2.0RC2","8.2.1","8.3.0","8.3.1","8.3.2","8.4.0","8.4.0RC3","8.4.0RC4","8.4.1","8.4.2","8.4.3","8.4.4","8.4.5","8.5.0","8.5.0RC1","8.5.0RC2","8.5.1","8.5.10","8.5.11","8.5.12","8.5.13","8.5.14","8.5.15","8.5.16","8.5.17","8.5.18","8.5.19","8.5.2","8.5.20","8.5.21","8.5.3","8.5.4","8.5.5","8.5.6","8.5.6RC1","8.5.7","8.5.8","8.5.9","9.0.0","9.0.0RC1","9.0.0RC3","9.0.0RC4","9.0.1","9.0.2","9.1.0","9.1.1","9.1.2","9.1.3","9.2.0","9.2.0RC2","9.2.1","9.2.2","9.2.3","9.2.4","9.2.5","9.2.6","9.2.7","9.2.8","9.2.9","9.3.0","9.3.1","9.3.2","9.3.3","9.3.4","9.3.5","9.3.6","9.3.7","9.3.8","9.3.9","9.4.0","9.4.0RC1","9.4.0RC2","9.4.1","9.4.2","9.4.3","9.4.4","9.4.5","9.4.6","9.4.7"]}],"products":[{"vendor":"concrete cms","product":"concrete cms"},{"vendor":"concretecms","product":"concrete_cms"}],"references":[{"url":"https://github.com/concretecms/concretecms/pull/12826","tags":["Exploit","Issue Tracking","Vendor Advisory","fix","web"]},{"url":"https://documentation.concretecms.org/9-x/developers/introduction/version-history/948-release-notes","tags":["Patch","Release Notes","Vendor Advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-3240","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-45fj-fvmm-xcc5"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/3xxx/CVE-2026-3240.json","tags":["advisory"]},{"url":"https://github.com/concretecms/concretecms","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-3240","title":"Concrete CMS below 9.4.8 is vulnerable to Stored XSS via Legacy form","description":"In Concrete CMS below version 9.4.8, a user with permission to edit a page with element Legacy form can perform a stored XSS attack towards high-privilege accounts via the Question field. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 4.8 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N Thanks minhnn42, namdi and quanlna2 from VCSLab-Viettel Cyber Security for reporting.","status":"published","published":"2026-03-04T02:15:53.4Z","modified":"2026-03-04T15:33:21.842Z","cvss":[{"version":"4.0","score":4.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","level":"medium","assessor":"cna"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T13:48:58.05327Z"}],"euvd":[{"id":"EUVD-2026-9358","description":"In Concrete CMS below version 9.4.8, a user with permission to edit a page with element Legacy form can perform a stored XSS attack towards high-privilege accounts via the Question field. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 4.8 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N Thanks minhnn42, namdi and quanlna2 from VCSLab-Viettel Cyber Security for reporting.","status":"published","published":"2026-03-04T02:15:53Z","modified":"2026-03-04T15:33:21Z","cvss":[{"version":"4.0","score":4.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T19:48:11.18109Z"}],"ghsa":[{"id":"GHSA-45fj-fvmm-xcc5","title":"Concrete CMS has a stored Cross-site Scripting (XSS) vulnerability","description":"In Concrete CMS below version 9.4.8, a user with permission to edit a page with element Legacy form can perform a stored XSS attack towards high-privilege accounts via the Question field. \n\nThe Concrete CMS security team thanks minhnn42, namdi and quanlna2 from VCSLab-Viettel Cyber Security for reporting.","status":"published","published":"2026-03-04T03:31:34Z","modified":"2026-03-04T21:36:27Z","cvss":[{"version":"4.0","score":4.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:39:31.060223Z"}],"nvd":[{"id":"CVE-2026-3240","description":"In Concrete CMS below version 9.4.8, a user with permission to edit a page with element Legacy form can perform a stored XSS attack towards high-privilege accounts via the Question field. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 4.8 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N Thanks minhnn42, namdi and quanlna2 from VCSLab-Viettel Cyber Security for reporting.","status":"published","published":"2026-03-04T03:16:04.94Z","modified":"2026-06-17T10:43:16.36Z","cvss":[{"version":"4.0","score":4.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"},{"version":"3.1","score":4.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:12:07.420927Z"}],"osv":[{"id":"CVE-2026-3240","title":"Concrete CMS below 9.4.8 is vulnerable to Stored XSS via Legacy form","description":"In Concrete CMS below version 9.4.8, a user with permission to edit a page with element Legacy form can perform a stored XSS attack towards high-privilege accounts via the Question field. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 4.8 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N Thanks minhnn42, namdi and quanlna2 from VCSLab-Viettel Cyber Security for reporting.","status":"published","published":"2026-03-04T02:15:53.4Z","modified":"2026-10-28T02:31:11.059689406Z","cvss":[{"version":"4.0","score":4.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:45:01.218144Z"},{"id":"GHSA-45fj-fvmm-xcc5","title":"Concrete CMS has a stored Cross-site Scripting (XSS) vulnerability","description":"In Concrete CMS below version 9.4.8, a user with permission to edit a page with element Legacy form can perform a stored XSS attack towards high-privilege accounts via the Question field. \n\nThe Concrete CMS security team thanks minhnn42, namdi and quanlna2 from VCSLab-Viettel Cyber Security for reporting.","status":"published","published":"2026-03-04T03:31:34Z","modified":"2026-03-04T21:56:20.612876Z","cvss":[{"version":"4.0","score":4.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:46:36.434231Z"}]}}