{"id":"CVE-2026-18119","state":"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.","publishedAt":"2026-09-14T19:54:11.734Z","updatedAt":"2026-09-14T20:07:08.323Z","severity":{"score":7,"label":"High","version":"4.0","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","source":"ConcreteCMS"},"assigner":"ConcreteCMS","products":["Concrete CMS Concrete CMS"],"affected":[{"vendor":"Concrete CMS","product":"Concrete CMS","defaultStatus":"unaffected","versions":[{"version":"5.0.0","status":"affected","lessThanOrEqual":"9.5.2","versionType":"git"}],"collectionURL":"https://github.com/concretecms/concretecms","repo":"https://github.com/concretecms/concretecms"}],"references":["https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes"],"weaknesses":["CWE-79"],"ingestedAt":"2026-10-29T20:11:10.572Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/18xxx/CVE-2026-18119.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-18119","state":"PUBLISHED","datePublished":"2026-09-14T19:54:11.734Z","dateUpdated":"2026-09-14T20:07:08.323Z","assignerShortName":"ConcreteCMS","assignerOrgId":"ff5b8ace-8b95-4078-9743-eac1ca5451de","dateReserved":"2026-07-28T18:02:02.837Z"},"containers":{"cna":{"title":"Concrete CMS below 9.5.3 is vulnerable to Stored XSS via unsanitized inline block custom style values","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Concrete CMS","product":"Concrete CMS","defaultStatus":"unaffected","versions":[{"version":"5.0.0","status":"affected","lessThanOrEqual":"9.5.2","versionType":"git"}],"collectionURL":"https://github.com/concretecms/concretecms","repo":"https://github.com/concretecms/concretecms"}],"references":[{"url":"https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes","tags":["release-notes"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"HIGH","userInteraction":"PASSIVE","vulnConfidentialityImpact":"LOW","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"HIGH","baseScore":7,"vectorString":"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"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-79","lang":"en","description":"CWE-79 Improper neutralization of input during web page generation ('cross-site scripting')","type":"CWE"}]}],"providerMetadata":{"shortName":"ConcreteCMS","orgId":"ff5b8ace-8b95-4078-9743-eac1ca5451de","dateUpdated":"2026-09-14T19:54:11.734Z"},"impacts":[{"capecId":"CAPEC-592","descriptions":[{"lang":"en","value":"CAPEC-592 Stored XSS"}]}],"credits":[{"lang":"en","value":"manhthuan","type":"finder"}],"source":{"defect":["HackerOne"],"advisory":"3781166","discovery":"EXTERNAL"},"x_generator":{"engine":"Vulnogram 1.0.5"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-14T20:06:50.657332Z","id":"CVE-2026-18119","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-14T20:07:08.323Z"}}]}}}