CVE-2026-46649

Received Received - Intake

Brute Force Authentication Bypass in Joplin Server

Publication date: 2026-09-21

Last updated on: 2026-09-21

Assigner: GitHub, Inc.

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.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-21

Last Modified

2026-09-21

Generated

2026-09-22

AI Q&A

2026-09-22

EPSS Evaluated

N/A

NVD

CVE-2026-46649

Affected Vendors & Products

Vendor	Product	Version / Range
joplin	joplin_server	3.7.2

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-307	The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame.

Attack-Flow Graph

Executive Summary

Joplin Server before version 3.7.2 has a vulnerability in the SSO login process. The GET /api/login_with_code/:id endpoint accepts a nine-digit authentication code valid for ten minutes without rate limiting. An attacker can repeatedly guess the code during an active SSO login to gain a full session token, allowing access to and modification of user notes, notebooks, and account settings.

Detection Guidance

Detecting this vulnerability requires monitoring for repeated failed SSO login attempts targeting the GET /api/login_with_code/:id endpoint. Check server logs for excessive requests to this endpoint within a short timeframe. No specific commands are provided in the context.

Impact Analysis

If you use Joplin Server prior to 3.7.2, an attacker could exploit this to gain unauthorized access to your account. They could read, modify, or delete your notes and notebooks, and change your account settings without your knowledge.

Compliance Impact

This vulnerability could lead to unauthorized access to sensitive data, potentially violating GDPR (data protection) and HIPAA (health information privacy) requirements. Unauthorized access may result in data breaches, leading to legal penalties and reputational damage.

Mitigation Strategies

Upgrade Joplin Server to version 3.7.2 or later to address the vulnerability. Implement rate limiting on the /api/login_with_code/:id endpoint to prevent brute force attacks. Review server logs for signs of exploitation attempts.

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