Vulnerability · Published Oct 9, 2026 · Assigned by GitHub_M
CVE-2026-57458Vikunja: Scoped API token can mint unrestricted OAuth session credentials
High 8.1
In plain English
A high-severity privilege mismanagement in vikunja from go-vikunja. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | code.vikunja.io/api | 2.4.0 | GHSA-v3p6-34mc-hj7v |
| Go | code.vikunja.io/api | no fix listed | GO-2026-6750 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| go-vikunja | vikunja | = 2.3.0 |
Weakness: CWE-269 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N