Vulnerability in Laurent22 Joplin

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.

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-55210?
CVE-2026-55210 is a high-severity vulnerability in Laurent22 Joplin, classified under Authentication Bypass by Spoofing. CVSS score: 7.4/10. Published 2026-09-21.
How severe is CVE-2026-55210?
High severity. CVSS v3 base score is 7.4 out of 10.