{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-8203", "assignerOrgId": "ff5b8ace-8b95-4078-9743-eac1ca5451de", "state": "PUBLISHED", "assignerShortName": "ConcreteCMS", "dateReserved": "2026-05-09T00:02:43.920Z", "datePublished": "2026-05-21T20:31:56.536Z", "dateUpdated": "2026-05-21T20:31:56.536Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "ff5b8ace-8b95-4078-9743-eac1ca5451de", "shortName": "ConcreteCMS", "dateUpdated": "2026-05-21T20:31:56.536Z"}, "title": "Concrete CMS 9.5.0 and below has Stored XSS on the height parameter", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-79", "description": "CWE-79 Improper neutralization of input during web page generation ('cross-site scripting')", "type": "CWE"}]}], "impacts": [{"capecId": "CAPEC-198", "descriptions": [{"lang": "en", "value": "CAPEC-198 XSS Targeting Error Pages"}]}], "affected": [{"vendor": "Concrete CMS", "product": "Concrete CMS", "collectionURL": "https://github.com/concretecms/concretecms", "repo": "https://github.com/concretecms/concretecms", "versions": [{"status": "affected", "version": "5", "lessThanOrEqual": "9.5.0", "versionType": "git"}], "defaultStatus": "unaffected"}], "descriptions": [{"lang": "en", "value": "Concrete CMS 9.5.0 and below has Stored XSS on the height parameter.\u00a0The controller does not validate or sanitize $height.\u00a0Any user with editor privileges can inject malicious JavaScript that executes in the context of any visitor's browser, potentially leading to session hijacking, credential theft, or other malicious actions.\u00a0The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of\u00a07.3 with vector\u00a0CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks\u00a0Alfin Joseph for reporting.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "Concrete CMS 9.5.0 and below has Stored XSS on the height parameter.&nbsp;<span>The controller does not validate or sanitize </span><code>$height</code><span>.&nbsp;</span><span>Any user with editor privileges can inject malicious JavaScript that executes in the context of any visitor's browser, potentially leading to session hijacking, credential theft, or other malicious actions.&nbsp;</span>The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of&nbsp;7.3 with vector&nbsp;CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks&nbsp;Alfin Joseph for reporting.&nbsp;<div></div><br><br>"}]}], "references": [{"url": "https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes", "tags": ["release-notes"]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "privilegesRequired": "HIGH", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "HIGH", "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": 7.3, "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}}], "credits": [{"lang": "en", "value": "Alfin Joseph", "type": "finder"}], "source": {"defect": ["HackerOne"], "advisory": "https://hackerone.com/reports/3607565", "discovery": "EXTERNAL"}, "x_generator": {"engine": "Vulnogram 1.0.2"}}}}

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{"cveTags": [], "descriptions": [{"lang": "en", "value": "Concrete CMS 9.5.0 and below has Stored XSS on the height parameter.\u00a0The controller does not validate or sanitize $height.\u00a0Any user with editor privileges can inject malicious JavaScript that executes in the context of any visitor's browser, potentially leading to session hijacking, credential theft, or other malicious actions.\u00a0The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of\u00a07.3 with vector\u00a0CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks\u00a0Alfin Joseph for reporting."}], "id": "CVE-2026-8203", "lastModified": "2026-05-21T21:16:33.380", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 7.3, "baseSeverity": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "HIGH", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "PASSIVE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:H/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", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de", "type": "Secondary"}]}, "published": "2026-05-21T21:16:33.380", "references": [{"source": "ff5b8ace-8b95-4078-9743-eac1ca5451de", "url": "https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes"}], "sourceIdentifier": "ff5b8ace-8b95-4078-9743-eac1ca5451de", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-79"}], "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de", "type": "Secondary"}]}

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