{"id":"CVE-2026-18119","aliases":["EUVD-2026-77805","GHSA-fjhh-g9g9-wm99"],"status":"published","title":"Concrete CMS below 9.5.3 is vulnerable to Stored XSS via unsanitized inline block custom style values","description":"Concrete CMS below 9.5.3 did not sanitize custom style values in the Block Design dialog before writing them into page CSS via a DOM sink, permitting stored cross-site scripting. An editor-level user could execute script in an administrator's session and escalate privileges. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.0 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Nguyen Manh Thuan for reporting.","severity":{"version":"4.0","score":7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00463,"percentile":0.4054,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-79"],"published":"2026-09-14T19:54:11Z","modified":"2026-11-11T02:30:38Z","products":[{"vendor":"concrete cms","product":"concrete cms"},{"vendor":"concretecms","product":"concrete_cms"}],"references":[{"url":"https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes","tags":["release-notes","Broken Link","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-18119","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-fjhh-g9g9-wm99"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/18xxx/CVE-2026-18119.json","tags":["advisory"]},{"url":"https://github.com/concretecms/concretecms","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-18119","title":"Concrete CMS below 9.5.3 is vulnerable to Stored XSS via unsanitized inline block custom style values","description":"Concrete CMS below 9.5.3 did not sanitize custom style values in the Block Design dialog before writing them into page CSS via a DOM sink, permitting stored cross-site scripting. An editor-level user could execute script in an administrator's session and escalate privileges. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.0 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Nguyen Manh Thuan for reporting.","status":"published","published":"2026-09-14T19:54:11.734Z","modified":"2026-09-14T20:07:08.323Z","cvss":[{"version":"4.0","score":7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:20:12.260247Z"}],"euvd":[{"id":"EUVD-2026-77805","description":"Concrete CMS below 9.5.3 did not sanitize custom style values in the Block Design dialog before writing them into page CSS via a DOM sink, permitting stored cross-site scripting. An editor-level user could execute script in an administrator's session and escalate privileges. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.0 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Nguyen Manh Thuan for reporting.","status":"published","published":"2026-09-14T19:54:11Z","modified":"2026-09-14T20:07:08Z","cvss":[{"version":"4.0","score":7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T17:28:19.383429Z"}],"ghsa":[{"id":"GHSA-fjhh-g9g9-wm99","title":"Concrete CMS below 9.5.3 did not sanitize custom style values in the Block Design dialog before...","description":"Concrete CMS below 9.5.3 did not sanitize custom style values in the Block Design dialog before writing them into page CSS via a DOM sink, permitting stored cross-site scripting. An editor-level user could execute script in an administrator's session and escalate privileges. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.0 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Nguyen Manh Thuan for reporting.","status":"published","published":"2026-09-14T21:31:44Z","modified":"2026-09-18T21:31:54Z","cvss":[{"version":"4.0","score":7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"},{"version":"3.1","score":9,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:12:12.006795Z"}],"nvd":[{"id":"CVE-2026-18119","description":"Concrete CMS below 9.5.3 did not sanitize custom style values in the Block Design dialog before writing them into page CSS via a DOM sink, permitting stored cross-site scripting. An editor-level user could execute script in an administrator's session and escalate privileges. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.0 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Nguyen Manh Thuan for reporting.","status":"published","published":"2026-09-14T20:16:42.563Z","modified":"2026-09-18T19:23:08.313Z","cvss":[{"version":"4.0","score":7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"},{"version":"3.1","score":9,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H","level":"critical","assessor":"primary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:12:47.335523Z"}],"osv":[{"id":"CVE-2026-18119","title":"Concrete CMS below 9.5.3 is vulnerable to Stored XSS via unsanitized inline block custom style values","description":"Concrete CMS below 9.5.3 did not sanitize custom style values in the Block Design dialog before writing them into page CSS via a DOM sink, permitting stored cross-site scripting. An editor-level user could execute script in an administrator's session and escalate privileges. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.0 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Nguyen Manh Thuan for reporting.","status":"published","published":"2026-09-14T19:54:11.734Z","modified":"2026-11-11T02:30:38.417170048Z","cvss":[{"version":"4.0","score":7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-79"],"updated_at":"2026-11-11T11:06:41.846566Z"}]}}