CVE-2026-40103: CWE-836: Use of Password Hash Instead of Password for Authentication in go-vikunja vikunja
Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, Vikunja's scoped API token enforcement for custom project background routes is method-confused. A token with only projects.background can successfully delete a project background, while a token with only projects.background_delete is rejected. This is a scoped-token authorization bypass. This vulnerability is fixed in 2.3.0.
AI Analysis
Technical Summary
CVE-2026-40103 is a medium-severity vulnerability in the open-source task management platform Vikunja (versions before 2.3.0). The vulnerability arises from a method confusion in scoped API token enforcement, where a token with the projects.background scope can perform delete operations on project backgrounds, bypassing intended authorization restrictions. Tokens with the more restrictive projects.background_delete scope are incorrectly rejected, indicating a logic flaw in permission checks. This scoped-token authorization bypass allows unauthorized deletion of project backgrounds. The vulnerability is addressed in Vikunja version 2.3.0.
Potential Impact
The vulnerability allows an attacker with a scoped API token limited to projects.background to delete project backgrounds, which should require the projects.background_delete scope. This leads to an authorization bypass impacting integrity, but does not affect confidentiality or availability. The CVSS score is 4.3 (medium severity), reflecting limited impact confined to unauthorized modification of project backgrounds.
Mitigation Recommendations
Upgrade Vikunja to version 2.3.0 or later, where this scoped-token authorization bypass is fixed. No other mitigation is indicated or required according to the available data.
CVE-2026-40103: CWE-836: Use of Password Hash Instead of Password for Authentication in go-vikunja vikunja
Description
Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, Vikunja's scoped API token enforcement for custom project background routes is method-confused. A token with only projects.background can successfully delete a project background, while a token with only projects.background_delete is rejected. This is a scoped-token authorization bypass. This vulnerability is fixed in 2.3.0.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-40103 is a medium-severity vulnerability in the open-source task management platform Vikunja (versions before 2.3.0). The vulnerability arises from a method confusion in scoped API token enforcement, where a token with the projects.background scope can perform delete operations on project backgrounds, bypassing intended authorization restrictions. Tokens with the more restrictive projects.background_delete scope are incorrectly rejected, indicating a logic flaw in permission checks. This scoped-token authorization bypass allows unauthorized deletion of project backgrounds. The vulnerability is addressed in Vikunja version 2.3.0.
Potential Impact
The vulnerability allows an attacker with a scoped API token limited to projects.background to delete project backgrounds, which should require the projects.background_delete scope. This leads to an authorization bypass impacting integrity, but does not affect confidentiality or availability. The CVSS score is 4.3 (medium severity), reflecting limited impact confined to unauthorized modification of project backgrounds.
Mitigation Recommendations
Upgrade Vikunja to version 2.3.0 or later, where this scoped-token authorization bypass is fixed. No other mitigation is indicated or required according to the available data.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-09T01:41:38.536Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69d9d9751cc7ad14da3f8745
Added to database: 4/11/2026, 5:17:41 AM
Last enriched: 4/18/2026, 2:04:58 PM
Last updated: 5/26/2026, 12:08:31 PM
Views: 113
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