Auth bypass in Getkirby Kirby
CVE-2026-42174
Kirby is an open-source content management system. Prior to versions 4.9.0 and 5.4.0, user avatar creation, replacement and deletion are not gated by user update permissions. This issue has been patched in versions 4.9.0 and 5.4.0.
Vulnerability class: Broken Access Control
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 (23.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 23.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
- Getkirby Kirby — versions < 4.9.0, >= 5.0.0, < 5.4.0
Weakness classification (CWE)
References
- github.com/getkirby/kirby/releases/tag/4.9.0 (Release Notes)
- github.com/getkirby/kirby/releases/tag/5.4.0 (Release Notes)
- github.com/getkirby/kirby/security/advisories/GHSA-39cp-6679-8xv2 (Patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-42174?
- CVE-2026-42174 is a medium-severity vulnerability in Getkirby Kirby, classified under Missing Authorization. CVSS score: 4.3/10. Published 2026-05-09.
- How severe is CVE-2026-42174?
- Medium severity. CVSS v3 base score is 4.3 out of 10.