CVE-2026-21896

MEDIUM EPSS 8.7%
Published Jan 8, 20265mo ago · Modified Jun 17, 20262w ago
5.8 CVSS 4.0
Medium
Find Similar
Published Jan 8, 2026 5mo ago
Last Modified Jun 17, 2026 2w ago

Description

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.

CVSS Details

Base Score
5.8
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity Low
Privileges Required Low
User Interaction A
Scope X

Threat Intelligence

EPSS Exploit Probability
8.7% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-863 Incorrect Authorization Authorization

Affected Products 1

VendorProductVersionRange
getkirbykirby*≥5.0.0  –  <5.2.2

References 3

  • github.com https://github.com/getkirby/kirby/commit/f5ce1347b427b819bf193acf11fd0da232f7af47
    Patch
  • github.com https://github.com/getkirby/kirby/releases/tag/5.2.2
    ProductRelease Notes
  • github.com https://github.com/getkirby/kirby/security/advisories/GHSA-4j78-4xrm-cr2f
    PatchVendor Advisory

Remediation

  • github.com https://github.com/getkirby/kirby/commit/f5ce1347b427b819bf193acf11fd0da232f7af47
    Patch
  • github.com https://github.com/getkirby/kirby/security/advisories/GHSA-4j78-4xrm-cr2f
    PatchVendor Advisory