CVE-2026-55210

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.

• https://github.com/laurent22/joplin/commit/b6d69d072919cbe769234f93d95ed21e1ec129b2
• https://github.com/laurent22/joplin/pull/15647
• https://github.com/laurent22/joplin/security/advisories/GHSA-5px3-4f5x-hjc5