CVE-2026-3240

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{"affected": [{"affectedData": [{"collectionURL": "https://github.com/concretecms/concretecms", "defaultStatus": "unaffected", "product": "Concrete CMS", "repo": "https://github.com/concretecms/concretecms", "vendor": "Concrete CMS", "versions": [{"lessThan": "9.4.8", "status": "affected", "version": "5", "versionType": "git"}]}], "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*", "matchCriteriaId": "BCBFD93E-6A10-4E9F-A31E-4A2C1FCD367C", "versionEndExcluding": "9.4.8", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In Concrete CMS below version 9.4.8, a\u00a0user with permission to edit a page with element Legacy form can perform a stored XSS attack towards high-privilege accounts via the\u00a0Question field.\u00a0The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 4.8 with vector\u00a0CVSS: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\u00a0minhnn42, namdi and quanlna2 from VCSLab-Viettel Cyber Security for reporting."}, {"lang": "es", "value": "En Concrete CMS, en versiones anteriores a la 9.4.8, un usuario con permiso para editar una p\u00e1gina con el elemento 'Legacy form' puede realizar un ataque de XSS almacenado dirigido a cuentas de alto privilegio a trav\u00e9s del campo Pregunta. El equipo de seguridad de Concrete CMS asign\u00f3 a esta vulnerabilidad una puntuaci\u00f3n CVSS v.4.0 de 4.8 con el 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. Gracias a minhnn42, namdi y quanlna2 de VCSLab-Viettel Cyber Security por informar."}], "id": "CVE-2026-3240", "lastModified": "2026-06-17T10:43:16.360", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 4.8, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "HIGH", "scope": "CHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 1.7, "impactScore": 2.7, "source": "nvd@nist.gov", "type": "Primary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 4.8, "baseSeverity": "MEDIUM", "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: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", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "LOW", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-3240", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-03-04T15:32:45.974969Z", "version": "2.0.3"}}]}, "published": "2026-03-04T03:16:04.940", "references": [{"source": "ff5b8ace-8b95-4078-9743-eac1ca5451de", "tags": ["Patch", "Release Notes", "Vendor Advisory"], "url": "https://documentation.concretecms.org/9-x/developers/introduction/version-history/948-release-notes"}, {"source": "ff5b8ace-8b95-4078-9743-eac1ca5451de", "tags": ["Exploit", "Issue Tracking", "Vendor Advisory"], "url": "https://github.com/concretecms/concretecms/pull/12826"}], "sourceIdentifier": "ff5b8ace-8b95-4078-9743-eac1ca5451de", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-79"}], "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[5,9.4.8)"}}], "enrichment": {"confidence": 98.0, "confidence_source": "matching", "scores": [{"score": 98.0, "source": "matching"}]}, "original": {"product": "Concrete CMS", "source": "cna", "vendor": "Concrete CMS"}, "product": "concrete_cms", "vendor": "concretecms"}], "analysis": {"en": {"generated_at": "2026-04-17T13:15:47.633535+00:00", "value": {"mitigation_remediation": ["Upgrade Concrete CMS to version 9.4.8 or later", "Remove or disable the Legacy form element from pages that are viewed by high\u2011privilege accounts", "Restrict edit permissions on pages that contain Legacy form elements to the minimum required users"], "summary": {"action": "Immediate Patch", "impact": "Stored Cross\u2011Site Scripting"}, "threat_synthesis": {"affected_systems": "All installations of Concrete CMS, version 9.4.8 and earlier, that use the Legacy form element on a page edit\u2011able by users, are affected. Any deployment where high\u2011privilege users can view pages containing this legacy form is at risk unless the CMS is upgraded beyond the affected version.", "description_and_impact": "Concrete CMS versions older than 9.4.8 permit a user who can edit a page that includes the Legacy form element to store malicious script payloads in the Question field. When a high\u2011privilege user later views that page, the stored script executes in the user\u2019s browser context, potentially allowing the attacker to capture credentials, hijack sessions, or perform other browser\u2011based abuses. The vulnerability is a classic input validation flaw classified as CWE\u201179. The impact is therefore a stored cross\u2011site scripting exposure that can affect the confidentiality and integrity of privileged accounts.", "risk_and_exploitability": "The CVE carries a CVSS v4.0 score of 4.8, indicating moderate severity. The EPSS score is reported as less than 1%, suggesting low current exploitation probability, and the vulnerability is not listed in CISA\u2019s KEV catalog. Exploitation requires only normal edit permissions on a page containing the Legacy form; after injection the payload is served to all users who view the page, particularly high\u2011privilege accounts. The likely attack vector is through the Question field of the Legacy form, inferred from the description because the supplied data does not explicitly state the entry point but the text indicates it lies there."}}}}, "created": "2026-03-04T14:53:18.905942+00:00", "updated": "2026-04-17T13:30:19.589167+00:00", "vendors": ["concretecms", "concretecms$PRODUCT$concrete_cms"]}