Kirby up to 5.2.1 Content Changes API authorization

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.4$0-$5k0.00

Summaryinfo

A vulnerability categorized as problematic has been discovered in Kirby up to 5.2.1. Affected is an unknown function of the component Content Changes API. The manipulation results in authorization. This vulnerability is reported as CVE-2026-21896. The attack can be launched remotely. No exploit exists. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Kirby up to 5.2.1. It has been classified as problematic. Affected is an unknown functionality of the component Content Changes API. The manipulation with an unknown input leads to a authorization vulnerability. CWE is classifying the issue as CWE-863. The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. This allows attackers to bypass intended access restrictions. This is going to have an impact on integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-21896 since 01/05/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. There are neither technical details nor an exploit publicly available.

Upgrading to version 5.2.2 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch f5ce1347b427b819bf193acf11fd0da232f7af47 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 5.6
VulDB Meta Temp Score: 5.4

VulDB Base Score: 5.4
VulDB Temp Score: 5.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.7
NVD Vector: 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Authorization
CWE: CWE-863 / CWE-285 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kirby 5.2.2
Patch: f5ce1347b427b819bf193acf11fd0da232f7af47

Timelineinfo

01/05/2026 CVE reserved
01/08/2026 +3 days Advisory disclosed
01/08/2026 +0 days VulDB entry created
02/02/2026 +25 days VulDB entry last update

Sourcesinfo

Advisory: GHSA-4j78-4xrm-cr2f
Status: Confirmed

CVE: CVE-2026-21896 (🔒)
GCVE (CVE): GCVE-0-2026-21896
GCVE (VulDB): GCVE-100-340152

Entryinfo

Created: 01/08/2026 19:44
Updated: 02/02/2026 22:36
Changes: 01/08/2026 19:44 (69), 02/02/2026 22:36 (11)
Complete: 🔍
Cache ID: 216::103

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