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CVE-2026-21896

Kirby is missing permission checks in the content changes API

Published: Jan 8, 2026Updated: Feb 2, 2026 Sources: CVE List NVD GHSACWE-863
NVD MITRE
5.7CVSSMEDIUM
EPSS Score
0.2%
Top 91.5%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

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 Vector Breakdown

AV:NAC:LPR:LUI:RS:UC:NI:HA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:LPrivileges Required
Low
UI:RUser Interaction
Required
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:HIntegrity
High
A:NAvailability
None
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Weaknesses

CWE-863

Affected Products

kirbygetkirby
On-prem
Web & CMS Plugins / cms-core
getkirby/cmsPackagistOSS Libraries
getkirbycommercialWeb & CMS Plugins
packagistpackage-ecosystemOSS Libraries

Attack Graph

Products CVE Techniques Tactics

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Exploitability

Official Patch Available

MITRE ATT&CK

2 techniques
Initial Access
View detailed technique mapping

References

https://github.com/getkirby/kirby/security/advisories/GHSA-4j78-4xrm-cr2f
github.com
https://github.com/getkirby/kirby/commit/f5ce1347b427b819bf193acf11fd0da232f7af47
github.com
https://github.com/getkirby/kirby/releases/tag/5.2.2
github.com
and 2 more references View all →

Timeline

Published
Jan 8, 2026
Last Updated
Feb 2, 2026

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