Vikunja's Scoped API tokens with projects.background permission can delete project backgrounds
Priority MEDIUM 58CWE-836Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · Low · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-863.
Summary
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.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00226 13th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed vikunja (go-vikunja): 2.3.0code.vikunja.io/api (Go): 2.3.0
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| go-vikunja | vikunja | before 2.3.0 | 2.3.0 | Patch available | CNA |
| — | code.vikunja.io/api (Go) | before 2.3.0 | 2.3.0 | Patch available | GHSA-v479-vf79-mg83 |
- vikunja Vendorgo-vikunja Affected before 2.3.0 Fixed in 2.3.0 Patch available CNA
- code.vikunja.io/api (Go) Vendor— Affected before 2.3.0 Fixed in 2.3.0 Patch available GHSA-v479-vf79-mg83
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:* | before 2.3.0 | Vulnerable | go-vikunja |
- cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:* Versions before 2.3.0 Vulnerable ·go-vikunja
Remediation
- Fix · CNA vikunja (go-vikunja) Fixed in 2.3.0
- Fix · GHSA-v479-vf79-mg83 code.vikunja.io/api (Go) Fixed in 2.3.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-40103
- 2026-10-03 Alias added: GHSA-v479-vf79-mg83
References
More go-vikunja Vikunja vulnerabilities
- TI-2026-21967 Vijkunja has Weak Password Policy Combined with Persistent Sessions After Password Change CVSS 3.1CRITICAL 9.1
- TI-2026-26971 Vikunja ahs a TOTP Two-Factor Authentication Bypass via OIDC Login Path CVSS 3.1CRITICAL 9.1
- TI-2026-26060 Vikunja Vulnerable to Link Share Hash Disclosure via ReadAll Endpoint Enables Permission Escalation CVSS 3.1HIGH 7.5
- TI-2026-20965 Vikunja Affected by XSS Via Task Preview CVSS 4.0HIGH 8.6
- TI-2026-27698 Vikunja Affected by Privilege Escalation via Project Reparenting CVSS 3.1HIGH 8.3
- TI-2026-25727 Vikunja’s Improper Access Control Enables Bypass of Administrator-Imposed Account Disablement CVSS 3.1HIGH 8.1
Sources
- CVE-2026-40103 · CVE Program
- CVE-2026-40103 · NVD
- FIRST EPSS
- GHSA-v479-vf79-mg83 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences