{"id":"CVE-2026-55210","state":"PUBLISHED","title":"Joplin: SAML SSO account takeover via email-based account linking (missing is_external check in ssoLogin)","description":"Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Prior to 3.7.2, Joplin Server's UserModel.ssoLogin() returns an existing account matched by an IdP-asserted email without checking the account's is_external flag. In deployments using mixed local and SAML authentication, an attacker whose IdP session can assert a local user's email can pass POST /api/saml, receive a session for that local account, and access or modify the victim's notes, files, and settings without knowing the local password. This issue is fixed in version 3.7.2.","publishedAt":"2026-09-21T21:14:31.267Z","updatedAt":"2026-09-22T13:07:10.486Z","severity":{"score":7.4,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["laurent22 joplin"],"affected":[{"vendor":"laurent22","product":"joplin","versions":[{"version":"< 3.7.2","status":"affected"}]}],"references":["https://github.com/laurent22/joplin/security/advisories/GHSA-5px3-4f5x-hjc5","https://github.com/laurent22/joplin/pull/15647","https://github.com/laurent22/joplin/commit/b6d69d072919cbe769234f93d95ed21e1ec129b2"],"weaknesses":["CWE-290"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/55xxx/CVE-2026-55210.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55210","state":"PUBLISHED","datePublished":"2026-09-21T21:14:31.267Z","dateUpdated":"2026-09-22T13:07:10.486Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-16T16:16:32.627Z"},"containers":{"cna":{"title":"Joplin: SAML SSO account takeover via email-based account linking (missing is_external check in ssoLogin)","descriptions":[{"lang":"en","value":"Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Prior to 3.7.2, Joplin Server's UserModel.ssoLogin() returns an existing account matched by an IdP-asserted email without checking the account's is_external flag. In deployments using mixed local and SAML authentication, an attacker whose IdP session can assert a local user's email can pass POST /api/saml, receive a session for that local account, and access or modify the victim's notes, files, and settings without knowing the local password. This issue is fixed in version 3.7.2."}],"affected":[{"vendor":"laurent22","product":"joplin","versions":[{"version":"< 3.7.2","status":"affected"}]}],"references":[{"url":"https://github.com/laurent22/joplin/security/advisories/GHSA-5px3-4f5x-hjc5","name":"https://github.com/laurent22/joplin/security/advisories/GHSA-5px3-4f5x-hjc5","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/laurent22/joplin/pull/15647","name":"https://github.com/laurent22/joplin/pull/15647","tags":["x_refsource_MISC"]},{"url":"https://github.com/laurent22/joplin/commit/b6d69d072919cbe769234f93d95ed21e1ec129b2","name":"https://github.com/laurent22/joplin/commit/b6d69d072919cbe769234f93d95ed21e1ec129b2","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.4,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-290","lang":"en","description":"CWE-290: Authentication Bypass by Spoofing","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-21T21:14:31.267Z"},"source":{"advisory":"GHSA-5px3-4f5x-hjc5","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-22T13:06:34.047429Z","id":"CVE-2026-55210","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-22T13:07:10.486Z"}}]}}}