CVE-2026-55210
Joplin: SAML SSO account takeover via email-based account linking (missing is_external check in ssoLogin)
CVSS Score
7.4
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-290 |
| Vendor | laurent22 |
| Product | joplin |
| Published | Sep 21, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None
Affected Versions
laurent22 / joplin
< 3.7.2