Is CVE-2026-21896 actively exploited?

CVE-2026-21896 has no public evidence of in-the-wild exploitation as of 2026-02-02.

What is the CVSS score for CVE-2026-21896?

CVE-2026-21896 has a CVSS score of 5.8 (MEDIUM severity). Vector: 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.

How do I patch CVE-2026-21896?

Patch guidance is available from getkirby security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2026-21896.

CVE-2026-21896 - remediation guidance & executive summary

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 Metrics

Vector: 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
Complexity: low
Privileges: low
User Action: active
Confidentiality: undefined
Integrity: undefined
Availability: undefined
Weaknesses: CWE-863 · Incorrect Authorization

Metadata

Primary Vendor: GETKIRBY
Published: 1/8/2026
Last Modified: 2/2/2026
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

getkirby : kirby

Remediation Guidance

Executive Summary

Cite this page

CVE-2026-21896. CVEDatabase.com. Retrieved 1 May 2026. https://cvedatabase.com/cve/CVE-2026-21896

View on NIST NVD

CVE-2026-21896 vulnerability