Joplin: SAML SSO account takeover via email-based account linking (missing is_external check in ssoLogin)
cve-program · CVE-2026-55210
PublishedJoplin 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.
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cve-program · CVE-2026-55210
PublishedJoplin: SAML SSO account takeover via email-based account linking (missing is_external check in ssoLogin)
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.
- Source published
- 21 Sep 2026 21:14:31 UTC
- Source modified
- 22 Sep 2026 13:07:10 UTC
- Saved here
- 23 Oct 2026 15:48:27 UTC
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CVSS 3.1 · 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N