CVE-2026-40103
Vikunja's Scoped API tokens with projects.background permission can delete project backgrounds
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.
INFO
Published Date :
April 10, 2026, 5:17 p.m.
Last Modified :
April 17, 2026, 10:03 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update Vikunja to version 2.3.0 or later.
- Verify API token scopes and permissions.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-40103.
| URL | Resource |
|---|---|
| https://github.com/go-vikunja/vikunja/commit/6a0f39b252a81fa4b19dc56dc889183acc9225ae | Patch |
| https://github.com/go-vikunja/vikunja/pull/2584 | Issue Tracking |
| https://github.com/go-vikunja/vikunja/releases/tag/v2.3.0 | Release Notes |
| https://github.com/go-vikunja/vikunja/security/advisories/GHSA-v479-vf79-mg83 | Exploit Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-40103 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-40103
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-40103 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-40103 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Apr. 17, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L Added CPE Configuration OR *cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:* versions up to (excluding) 2.3.0 Added Reference Type GitHub, Inc.: https://github.com/go-vikunja/vikunja/commit/6a0f39b252a81fa4b19dc56dc889183acc9225ae Types: Patch Added Reference Type GitHub, Inc.: https://github.com/go-vikunja/vikunja/pull/2584 Types: Issue Tracking Added Reference Type GitHub, Inc.: https://github.com/go-vikunja/vikunja/releases/tag/v2.3.0 Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/go-vikunja/vikunja/security/advisories/GHSA-v479-vf79-mg83 Types: Exploit, Vendor Advisory -
New CVE Received by [email protected]
Apr. 10, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N Added CWE CWE-836 Added Reference https://github.com/go-vikunja/vikunja/commit/6a0f39b252a81fa4b19dc56dc889183acc9225ae Added Reference https://github.com/go-vikunja/vikunja/pull/2584 Added Reference https://github.com/go-vikunja/vikunja/releases/tag/v2.3.0 Added Reference https://github.com/go-vikunja/vikunja/security/advisories/GHSA-v479-vf79-mg83