Auth bypass in Go-Vikunja Vikunja
CVE-2026-123503
Vikunja before 2.7.1 contains an improper authorization vulnerability in canDoBucket that allows users with project write access to delete buckets via a mismatched view ID. Attackers can request deletion through another view's bucket endpoint to bypass the last-bucket rule, leaving dangling default/done bucket references and inconsistent task buckets.
Vulnerability class: IDOR (Insecure Direct Object Reference)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L.
EPSS exploit prediction
EPSS: 0.002 (14.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 15th percentile — 14.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
The 30-day trend appears once there are two daily scores.
Affected products
Weakness classification (CWE)
References
- github.com/go-vikunja/vikunja/security/advisories/GHSA-9xh7-5jg8-mf43 (vendor-advisory)
- www.vulncheck.com/advisories/vikunja-before-2.7.1-improper-authorization-in-kan… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-123503?
- CVE-2026-123503 is a medium-severity vulnerability in Go-Vikunja Vikunja, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 5.4/10. Published 2026-11-08.
- How severe is CVE-2026-123503?
- Medium severity. CVSS v3 base score is 5.4 out of 10.