Auth bypass in Getkirby Kirby
CVE-2026-42051
Kirby is an open-source content management system. Prior to versions 4.9.0 and 5.4.0, the system API endpoint leaks license data and installed version to authenticated users. 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:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.003 (23.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 24th percentile — 23.7% 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-x68m-c7jf-2572 (Patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-42051?
- CVE-2026-42051 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-2026-42051?
- Medium severity. CVSS v3 base score is 4.3 out of 10.