What’s Vulnerable › Vulnerabilities

CVE-2026-40103: Vikunja's Scoped API tokens with projects.background permission can delete project backgrounds

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-04-10 · updated 2026-10-26
• Weakness: CWE-836

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.

Affected products

• go-vikunja vikunja: before 2.3.0 — fixed in 2.3.0

How to fix

Upgrade to a fixed version: go-vikunja vikunja 2.3.0. Check the vendor advisory for mitigations.

References

• https://github.com/go-vikunja/vikunja/commit/6a0f39b252a81fa4b19dc56dc889183acc9225ae
• https://github.com/go-vikunja/vikunja/pull/2584
• https://github.com/go-vikunja/vikunja/releases/tag/v2.3.0
• https://github.com/go-vikunja/vikunja/security/advisories/GHSA-v479-vf79-mg83

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