{"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":"2026-08-31T12:27:40.249Z"},"containers":{"cna":{"providerMetadata":{"orgId":"e51fbebd-6053-4e49-959f-1b94eeb69a2c","shortName":"eclipse","dateUpdated":"2026-08-31T12:27:40.249Z"},"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":"INTERNAL"},"x_generator":{"engine":"Vulnogram 1.0.5"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-28T15:03:52.629478Z","id":"CVE-2026-18918","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-08-28T15:04:16.704Z"}}]}}