{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-18918", "assignerOrgId": "e51fbebd-6053-4e49-959f-1b94eeb69a2c", "state": "PUBLISHED", "assignerShortName": "eclipse", "dateReserved": "2026-08-05T07:44:04.388Z", "datePublished": "2026-08-28T08:54:07.990Z", "dateUpdated": "2026-08-28T08:54:07.990Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "e51fbebd-6053-4e49-959f-1b94eeb69a2c", "shortName": "eclipse", "dateUpdated": "2026-08-28T08:54:07.990Z"}, "title": "OAuth 1.0 session-fixation chain via unauthenticated provisional-consumer registration and insecure v1_0Allowed default", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-863", "description": "CWE-863", "type": "CWE"}]}], "impacts": [{"capecId": "CAPEC-114", "descriptions": [{"lang": "en", "value": "CAPEC-114"}]}], "affected": [{"vendor": "Eclipse Foundation", "product": "Eclipse Lyo", "versions": [{"status": "affected", "version": "2.0.0", "lessThan": "7.0.0", "versionType": "custom"}], "defaultStatus": "unaffected"}], "descriptions": [{"lang": "en", "value": "In Eclipse Lyo versions 2.0.0 to 7.0.0, OAuth server authorization checks can be bypassed when the 2-legged auth is supported by the server. In those cases, application that based their authz filters upon Lyo-provided `AbstractAdapterCredentialsFilter`, are vulnerable. An attacked can create a provisional trusted client (valid use-case) but then it can be used as a trusted client immediately without requiring the administrator approval to clear the provisional status. The 3-legged path requiring user interaction is not vulnerable and rejects provisional clients.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<p>In Eclipse Lyo versions 2.0.0 to 7.0.0, OAuth server authorization checks can be bypassed when the 2-legged auth is supported by the server. In those cases, application that based their authz filters upon Lyo-provided `AbstractAdapterCredentialsFilter`, are vulnerable. An attacked can create a provisional trusted client (valid use-case) but then it can be used as a trusted client immediately without requiring the administrator approval to clear the provisional status. The 3-legged path requiring user interaction is not vulnerable and rejects provisional clients.</p>"}]}], "references": [{"url": "https://github.com/eclipse-lyo/lyo/releases/tag/v6.0.1.Final"}, {"url": "https://github.com/eclipse-lyo/lyo/releases/tag/v7.0.0.Beta3"}, {"url": "https://gitlab.eclipse.org/security/cve-assignment/-/work_items/221"}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "subConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "subIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "YES", "Recovery": "USER", "valueDensity": "CONCENTRATED", "vulnerabilityResponseEffort": "LOW", "providerUrgency": "RED", "version": "4.0", "baseSeverity": "CRITICAL", "baseScore": 9.1, "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/AU:Y/R:U/V:C/RE:L/U:Red"}}], "credits": [{"lang": "en", "value": "Eclipse Foundation Security Team", "type": "finder"}], "source": {"discovery": "UNKNOWN"}, "x_generator": {"engine": "Vulnogram 1.0.5"}}}}

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Eclipse Lyo", "vendor": "Eclipse Foundation", "versions": [{"lessThan": "7.0.0", "status": "affected", "version": "2.0.0", "versionType": "custom"}]}], "source": "emo@eclipse.org"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In Eclipse Lyo versions 2.0.0 to 7.0.0, OAuth server authorization checks can be bypassed when the 2-legged auth is supported by the server. In those cases, application that based their authz filters upon Lyo-provided `AbstractAdapterCredentialsFilter`, are vulnerable. An attacked can create a provisional trusted client (valid use-case) but then it can be used as a trusted client immediately without requiring the administrator approval to clear the provisional status. The 3-legged path requiring user interaction is not vulnerable and rejects provisional clients."}], "id": "CVE-2026-18918", "lastModified": "2026-08-28T12:16:27.150", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "YES", "Recovery": "USER", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 9.1, "baseSeverity": "CRITICAL", "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": "RED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "CONCENTRATED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/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:Y/R:U/V:C/RE:L/U:Red", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "LOW"}, "source": "emo@eclipse.org", "type": "Secondary"}]}, "published": "2026-08-28T12:16:27.150", "references": [{"source": "emo@eclipse.org", "url": "https://github.com/eclipse-lyo/lyo/releases/tag/v6.0.1.Final"}, {"source": "emo@eclipse.org", "url": "https://github.com/eclipse-lyo/lyo/releases/tag/v7.0.0.Beta3"}, {"source": "emo@eclipse.org", "url": "https://gitlab.eclipse.org/security/cve-assignment/-/work_items/221"}], "sourceIdentifier": "emo@eclipse.org", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-863"}], "source": "emo@eclipse.org", "type": "Primary"}]}

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