CVE-2026-40103

Name: CVE-2026-40103
Creator: NVD / NIST
Published: 2026-04-10T17:17:13.143+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.4/10EPSS 0.22%

Last modified Jun 17, 2026

CVE-2026-40103 is a medium-severity vulnerability rated 5.4/10 on the CVSS scale. 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. EPSS estimates a 0.22% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

5.4/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L

EPSS Probability

0.22%

12.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-836

Affected Software

Vendor	Product	Versions
Vikunja	Vikunja	< 2.3.0

References

https://github.com/go-vikunja/vikunja/commit/6a0f39b252a81fa4b19dc56dc889183acc9225aePatch
https://github.com/go-vikunja/vikunja/pull/2584Issue Tracking
https://github.com/go-vikunja/vikunja/releases/tag/v2.3.0Release Notes
https://github.com/go-vikunja/vikunja/security/advisories/GHSA-v479-vf79-mg83Exploit, Vendor Advisory

Timeline

Published: Apr 10, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-40103?

How severe is CVE-2026-40103?

CVE-2026-40103 has a CVSS score of 5.4/10 (MEDIUM severity). The EPSS model estimates a 0.22% probability of exploitation in the next 30 days.

How do I fix CVE-2026-40103?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-40103?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST