CVE-2026-40103
MEDIUMDescription
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.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Exploit Intelligence
Low risk: more likely to be exploited than 13% of all known CVEs.
References
Related Vulnerabilities
Other CWE-836 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2017-7927 | High | 7.3 | 18% | - | - |
| CVE-2023-34132 | Critical | 9.8 | 7.7% | - | Fix |
| CVE-2022-32282 | High | 8.8 | 1.8% | - | - |
| CVE-2021-23857 | Critical | 10.0 | 1.2% | - | - |
| CVE-2023-23614 | High | 8.8 | 1.0% | - | Fix |
| CVE-2023-23450 | Medium | 6.2 | 0.7% | - | Fix |
Common questions
How do I fix CVE-2026-40103?
Upgrade vikunja to 2.3.0 or later.
Is CVE-2026-40103 being actively exploited?
Not that we know of. CVE-2026-40103 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.22% is the estimated probability that it will be exploited in the next 30 days. That is higher than 13% of all scored CVEs.
How severe is CVE-2026-40103?
CVE-2026-40103 has a CVSS v3 base score of 4.3, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-40103 affect?
Published advisories record a fix for vikunja (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2026-40103
Markdown
[](https://tridentstack.com/cve/CVE-2026-40103)HTML
<a href="https://tridentstack.com/cve/CVE-2026-40103"><img src="https://tridentstack.com/cve/badge/CVE-2026-40103.svg" alt="CVE-2026-40103"></a>Find and fix vulnerabilities across your fleet
TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.
This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-17.