{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-8428", "assignerOrgId": "ff5b8ace-8b95-4078-9743-eac1ca5451de", "state": "PUBLISHED", "assignerShortName": "ConcreteCMS", "dateReserved": "2026-05-12T18:07:11.189Z", "datePublished": "2026-05-21T20:24:11.572Z", "dateUpdated": "2026-05-21T20:24:11.572Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "ff5b8ace-8b95-4078-9743-eac1ca5451de", "shortName": "ConcreteCMS", "dateUpdated": "2026-05-21T20:24:11.572Z"}, "title": "CSRF token is not validated in the core CMS update controller for Concrete CMS 9.5.0 and below", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-352", "description": "CWE-352 Cross-Site request forgery (CSRF)", "type": "CWE"}]}, {"descriptions": [{"lang": "en", "cweId": "CWE-829", "description": "CWE-829 Inclusion of functionality from untrusted control sphere", "type": "CWE"}]}], "impacts": [{"capecId": "CAPEC-186", "descriptions": [{"lang": "en", "value": "CAPEC-186 Malicious Software Update"}]}], "affected": [{"vendor": "Concrete CMS", "product": "Concrete CMS", "collectionURL": "https://github.com/concretecms/concretecms", "repo": "https://github.com/concretecms/concretecms", "versions": [{"status": "affected", "version": "5.0", "lessThanOrEqual": "9.5.0", "versionType": "git"}], "defaultStatus": "unaffected"}], "descriptions": [{"lang": "en", "value": "Concrete CMS 9.5.0 and below emits a CSRF token in the local_available_update.php view ($token->output('do_update')) but the corresponding do_update() method in concrete/controllers/single_page/dashboard/system/update/update.php never calls $this->token->validate('do_update'). The form is rendered as a POST form, meaning the token reaches the browser, but because the controller discards it without verification, an attacker can craft a cross-site POST that triggers a core CMS update to an attacker-specified version string.\u00a0\u00a0In order to be vulnerable, theictim must be passing canUpgrade()anda valid update version must be present under DIR_CORE_UPDATES.\u00a0The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of\u00a07.5 with vector\u00a0CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks\u00a0https://github.com/maru1009\u00a0for reporting.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "Concrete CMS 9.5.0 and below emits a CSRF token in the <code>local_available_update.php</code> view (<code>$token-&gt;output('do_update')</code>) but the corresponding <code>do_update()</code> method in <code>concrete/controllers/single_page/dashboard/system/update/update.php</code> never calls <code>$this-&gt;token-&gt;validate('do_update')</code>. The form is rendered as a POST form, meaning the token reaches the browser, but because the controller discards it without verification, an attacker can craft a cross-site POST that triggers a core CMS update to an attacker-specified version string.&nbsp;&nbsp;In order to be vulnerable, theictim must be passing <code>canUpgrade()and</code>a valid update version must be present under <code>DIR_CORE_UPDATES</code>.&nbsp;The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of&nbsp;7.5 with vector&nbsp;CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks&nbsp;https://github.com/maru1009&nbsp;for reporting.<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": "NONE", "userInteraction": "ACTIVE", "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": 7.5, "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}}], "source": {"discovery": "UNKNOWN"}, "x_generator": {"engine": "Vulnogram 1.0.2"}}}}

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{"cveTags": [], "descriptions": [{"lang": "en", "value": "Concrete CMS 9.5.0 and below emits a CSRF token in the local_available_update.php view ($token->output('do_update')) but the corresponding do_update() method in concrete/controllers/single_page/dashboard/system/update/update.php never calls $this->token->validate('do_update'). The form is rendered as a POST form, meaning the token reaches the browser, but because the controller discards it without verification, an attacker can craft a cross-site POST that triggers a core CMS update to an attacker-specified version string.\u00a0\u00a0In order to be vulnerable, theictim must be passing canUpgrade()anda valid update version must be present under DIR_CORE_UPDATES.\u00a0The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of\u00a07.5 with vector\u00a0CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks\u00a0https://github.com/maru1009\u00a0for reporting."}], "id": "CVE-2026-8428", "lastModified": "2026-05-21T21:16:34.387", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 7.5, "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": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "ACTIVE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/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": "2026-05-21T21:16:34.387", "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-352"}, {"lang": "en", "value": "CWE-829"}], "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de", "type": "Secondary"}]}

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