CVE-2026-46649

Joplin: SSO Auth Code Login Missing Rate Limiting — 9-Digit Numeric Code Brute-Forceable via Unprotected Endpoint

Published 21 Sep 2026 • Updated 21 Sep 2026

Severity: CRITICAL

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 GET /api/login_with_code/:id endpoint accepts a nine-digit SSO authentication code with a ten-minute lifetime without applying limiterLoginBruteForce. An unauthenticated attacker who targets a user during an active SSO login can make unlimited guesses, and a correct code returns a full session token that permits access to and modification of the user's notes, notebooks, and account settings. This issue is fixed in version 3.7.2.

Affected products (1)

• laurent22 joplin

Problem types

• CWE-307: Improper Restriction of Excessive Authentication Attempts

References (4)

• https://github.com/laurent22/joplin/security/advisories/GHSA-6vwc-4hrg-qp5h
• https://github.com/laurent22/joplin/pull/15433
• https://github.com/laurent22/joplin/commit/fd8c1fb53f98f689e846dc164e39f307f09b684d
• https://github.com/laurent22/joplin/tree/v3.7.2