{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-34840","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-03-30T20:52:53.284Z","datePublished":"2026-04-02T18:52:48.274Z","dateUpdated":"2026-04-02T20:20:13.291Z"},"containers":{"cna":{"title":"OneUptime SSO: Multi-Assertion Identity Injection via Decoupled Signature Verification","problemTypes":[{"descriptions":[{"cweId":"CWE-347","lang":"en","description":"CWE-347: Improper Verification of Cryptographic Signature","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":8.1,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","version":"3.1"}}],"references":[{"name":"https://github.com/OneUptime/oneuptime/security/advisories/GHSA-5w5c-766x-265g","tags":["x_refsource_CONFIRM"],"url":"https://github.com/OneUptime/oneuptime/security/advisories/GHSA-5w5c-766x-265g"},{"name":"https://github.com/OneUptime/oneuptime/commit/2fd7ede52f60444710628d6c1b34dee2ef9e57d1","tags":["x_refsource_MISC"],"url":"https://github.com/OneUptime/oneuptime/commit/2fd7ede52f60444710628d6c1b34dee2ef9e57d1"},{"name":"https://github.com/OneUptime/oneuptime/releases/tag/10.0.42","tags":["x_refsource_MISC"],"url":"https://github.com/OneUptime/oneuptime/releases/tag/10.0.42"}],"affected":[{"vendor":"OneUptime","product":"oneuptime","versions":[{"version":"< 10.0.42","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-04-02T18:52:48.274Z"},"descriptions":[{"lang":"en","value":"OneUptime is an open-source monitoring and observability platform. Prior to version 10.0.42, OneUptime's SAML SSO implementation (App/FeatureSet/Identity/Utils/SSO.ts) has decoupled signature verification and identity extraction. isSignatureValid() verifies the first <Signature> element in the XML DOM using xml-crypto, while getEmail() always reads from assertion[0] via xml2js. An attacker can prepend an unsigned assertion containing an arbitrary identity before a legitimately signed assertion, resulting in authentication bypass. This issue has been patched in version 10.0.42."}],"source":{"advisory":"GHSA-5w5c-766x-265g","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-04-02T20:20:03.529115Z","id":"CVE-2026-34840","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"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":"2026-04-02T20:20:13.291Z"}}]}}