{"id":"CVE-2026-34840","state":"PUBLISHED","title":"OneUptime SSO: Multi-Assertion Identity Injection via Decoupled Signature Verification","description":"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.","publishedAt":"2026-04-02T18:52:48.274Z","updatedAt":"2026-04-02T20:20:13.291Z","severity":{"score":8.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["OneUptime oneuptime"],"affected":[{"vendor":"OneUptime","product":"oneuptime","versions":[{"version":"< 10.0.42","status":"affected"}]}],"references":["https://github.com/OneUptime/oneuptime/security/advisories/GHSA-5w5c-766x-265g","https://github.com/OneUptime/oneuptime/commit/2fd7ede52f60444710628d6c1b34dee2ef9e57d1","https://github.com/OneUptime/oneuptime/releases/tag/10.0.42"],"weaknesses":["CWE-347"],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/34xxx/CVE-2026-34840.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-34840","state":"PUBLISHED","datePublished":"2026-04-02T18:52:48.274Z","dateUpdated":"2026-04-02T20:20:13.291Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-03-30T20:52:53.284Z"},"containers":{"cna":{"title":"OneUptime SSO: Multi-Assertion Identity Injection via Decoupled Signature Verification","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."}],"affected":[{"vendor":"OneUptime","product":"oneuptime","versions":[{"version":"< 10.0.42","status":"affected"}]}],"references":[{"url":"https://github.com/OneUptime/oneuptime/security/advisories/GHSA-5w5c-766x-265g","name":"https://github.com/OneUptime/oneuptime/security/advisories/GHSA-5w5c-766x-265g","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/OneUptime/oneuptime/commit/2fd7ede52f60444710628d6c1b34dee2ef9e57d1","name":"https://github.com/OneUptime/oneuptime/commit/2fd7ede52f60444710628d6c1b34dee2ef9e57d1","tags":["x_refsource_MISC"]},{"url":"https://github.com/OneUptime/oneuptime/releases/tag/10.0.42","name":"https://github.com/OneUptime/oneuptime/releases/tag/10.0.42","tags":["x_refsource_MISC"]}],"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"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-347","lang":"en","description":"CWE-347: Improper Verification of Cryptographic Signature","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-04-02T18:52:48.274Z"},"source":{"advisory":"GHSA-5w5c-766x-265g","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","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"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-04-02T20:20:13.291Z"}}]}}}