{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-90447", "assignerOrgId": "7d14cffa-0d7d-4270-9dc0-52cabd5a23a6", "state": "PUBLISHED", "assignerShortName": "icscert", "dateReserved": "2026-09-11T21:00:07.497Z", "datePublished": "2026-09-11T21:48:51.996Z", "dateUpdated": "2026-09-11T21:48:51.996Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "7d14cffa-0d7d-4270-9dc0-52cabd5a23a6", "shortName": "icscert", "dateUpdated": "2026-09-11T21:48:51.996Z"}, "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-290", "description": "CWE-290 Authentication bypass by spoofing", "type": "CWE"}]}], "affected": [{"vendor": "CISA", "product": "Malcolm", "repo": "https://github.com/cisagov/Malcolm", "versions": [{"status": "affected", "version": "0", "lessThan": "v26.06.0", "versionType": "custom"}, {"status": "unaffected", "version": "v26.06.0"}], "defaultStatus": "unaffected"}], "descriptions": [{"lang": "en", "value": "A routing rule selects between two different authentication mechanisms for the same downstream service based on the value of a client-supplied request header, rather than on any property the client cannot control. An authenticated user in possession of a shared service credential can set this header to route around the primary role-based authorization check and reach the alternate path's fixed, elevated role instead. This allows a low-privileged authenticated attacker who knows the shared credential to perform actions reserved for a higher-privileged role.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<div><div>A routing rule selects between two different authentication mechanisms for the same downstream service based on the value of a client-supplied request header, rather than on any property the client cannot control. An authenticated user in possession of a shared service credential can set this header to route around the primary role-based authorization check and reach the alternate path's fixed, elevated role instead. This allows a low-privileged authenticated attacker who knows the shared credential to perform actions reserved for a higher-privileged role.</div></div>"}]}], "references": [{"url": "https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2026/icsa-26-254-01.json", "tags": ["government-resource", "vendor-advisory"]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "subConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "subIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "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": 7.1, "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N"}}], "solutions": [{"lang": "en", "value": "The latest version of Malcolm (September 2026 or later) fixes these vulnerabilities. Affected users are encouraged to update their instance of Malcolm to the latest version.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<div><div>The latest version of Malcolm (September 2026 or later) fixes these vulnerabilities. Affected users are encouraged to update their instance of Malcolm to the latest version.</div></div>"}]}], "source": {"discovery": "UNKNOWN"}, "x_generator": {"engine": "Vulnogram 1.0.5"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Malcolm", "repo": "https://github.com/cisagov/Malcolm", "vendor": "CISA", "versions": [{"lessThan": "v26.06.0", "status": "affected", "version": "0", "versionType": "custom"}, {"status": "unaffected", "version": "v26.06.0"}]}], "source": "ics-cert@hq.dhs.gov"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "A routing rule selects between two different authentication mechanisms for the same downstream service based on the value of a client-supplied request header, rather than on any property the client cannot control. An authenticated user in possession of a shared service credential can set this header to route around the primary role-based authorization check and reach the alternate path's fixed, elevated role instead. This allows a low-privileged authenticated attacker who knows the shared credential to perform actions reserved for a higher-privileged role."}], "id": "CVE-2026-90447", "lastModified": "2026-09-11T22:16:46.797", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 7.1, "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": "LOW", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/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": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "ics-cert@hq.dhs.gov", "type": "Secondary"}]}, "published": "2026-09-11T22:16:46.797", "references": [{"source": "ics-cert@hq.dhs.gov", "url": "https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2026/icsa-26-254-01.json"}], "sourceIdentifier": "ics-cert@hq.dhs.gov", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-290"}], "source": "ics-cert@hq.dhs.gov", "type": "Primary"}]}

{}

{"created": "2026-09-12T08:00:11.012000+00:00", "title": "Privilege Escalation via Header\u2011Based Authentication Bypass in Malcolm", "updated": "2026-09-13T16:15:14.625980+00:00", "vendors": []}