Auth bypass in Go-Vikunja Vikunja
CVE-2026-91984
Vikunja before 2.6.0 fails to validate that user-supplied project_view_id in task-position requests belongs to the task's project. Authenticated attackers can insert task position rows into arbitrary other tenant project views via POST or PUT task-position endpoints.
Vulnerability class: IDOR (Insecure Direct Object Reference)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (18.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 18th percentile — 18.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
Weakness classification (CWE)
References
- github.com/go-vikunja/vikunja/security/advisories/GHSA-w39f-h553-h2mx (vendor-advisory)
- www.vulncheck.com/advisories/vikunja-before-2.6.0-broken-object-level-authoriza… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-91984?
- CVE-2026-91984 is a medium-severity vulnerability in Go-Vikunja Vikunja, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 4.3/10. Published 2026-09-15.
- How severe is CVE-2026-91984?
- Medium severity. CVSS v3 base score is 4.3 out of 10.