Auth bypass in Getkirby Kirby
CVE-2026-21896
Kirby is an open-source content management system. From versions 5.0.0 to 5.2.1, Kirby is missing permission checks in the content changes API. This vulnerability affects all Kirby sites where user permissions are configured to prevent specific role(s) from performing write actions, specifically by disabling the update permission with the intent to prevent modifications to site content. This vulnerability does not affect those who have not altered the deviated from default user permissions. This issue has been patched in version 5.2.2.
Vulnerability class: Broken Access Control
EPSS: 0.002 (8.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.7 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:N.
Affected products
- Getkirby Kirby — versions >= 5.0.0, < 5.2.2
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Patch, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-21896?
- CVE-2026-21896 is a medium-severity vulnerability in Getkirby Kirby, classified under Incorrect Authorization. CVSS score: 5.7/10. Published 2026-01-08.
- How severe is CVE-2026-21896?
- Medium severity. CVSS v3 base score is 5.7 out of 10.