{"id":"CVE-2026-18119","title":"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","summary":"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 administra…","severity":"critical","cvss":9,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H","cwe":["CWE-79"],"vendor":"concretecms","product":"concrete_cms","affected":["concrete_cms < 9.5.3"],"patched":["concrete_cms 9.5.3"],"published":"2026-09-14","updated":"2026-09-18","sourceUpdated":"2026-09-18T19:23:08.313","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-18119","references":[{"url":"https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes","label":"ff5b8ace-8b95-4078-9743-eac1ca5451de"}],"tags":["nvd","cve.org","score-dispute"],"epss":0.00312,"epssPercentile":0.24273,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-14T20:06:50.657332Z"},"scores":{"nvd":9,"cna":7},"ingestedAt":"2026-09-14T20:14:21.144Z","slug":"CVE-2026-18119","body":"## Overview\n\nConcrete 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.\n\n## Affected\n\n- `concrete_cms < 9.5.3`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `concrete_cms 9.5.3`","depth":"midnight","depthScore":50,"depthScoreParts":{"impact":49.5,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":207464,"id":"CVE-2026-18119","ts":1789761014717,"field":"cvss","old":"7","new":"9"},{"seq":207463,"id":"CVE-2026-18119","ts":1789761014717,"field":"severity","old":"high","new":"critical"}]}