Resource exhaustion in Go-Vikunja Vikunja
CVE-2026-91971
Vikunja before 2.6.0 fails to apply pixel decode limits to avatar and project-background upload endpoints, allowing authenticated users to upload crafted images that decode to excessive pixel counts. Attackers can upload small images with extreme aspect ratios that consume significant CPU and memory during processing, causing denial of service through repeated or concurrent uploads.
Vulnerability class: DoS (Denial of Service)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.004 (37.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 38th percentile — 37.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
Weakness classification (CWE)
References
- github.com/go-vikunja/vikunja/security/advisories/GHSA-4vh2-39rq-rq8j (vendor-advisory)
- www.vulncheck.com/advisories/vikunja-before-2.6.0-denial-of-service-via-avatar-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-91971?
- CVE-2026-91971 is a medium-severity vulnerability in Go-Vikunja Vikunja, classified under Uncontrolled Resource Consumption. CVSS score: 6.5/10. Published 2026-09-15.
- How severe is CVE-2026-91971?
- Medium severity. CVSS v3 base score is 6.5 out of 10.