getkirby up to 4.8.x/5.3.x authorization

Summaryinfo

A vulnerability was found in getkirby kirby up to 4.8.x/5.3.x and classified as problematic. Affected by this issue is some unknown functionality. Executing a manipulation can lead to authorization. This vulnerability is tracked as CVE-2026-40099. The attack can be launched remotely. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in getkirby kirby up to 4.8.x/5.3.x. This vulnerability affects an unknown code. The manipulation with an unknown input leads to a authorization vulnerability. The CWE definition for the vulnerability is 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. As an impact it is known to affect integrity. CVE summarizes:

Kirby is an open-source content management system. Kirby's user permissions control which user role is allowed to perform specific actions to content models in the CMS. These permissions are defined for each role in the user blueprint (`site/blueprints/users/...`). It is also possible to customize the permissions for each target model in the model blueprints (such as in `site/blueprints/pages/...`) using the `options` feature. The permissions and options together control the authorization of user actions. For pages, Kirby provides the `pages.create` and `pages.changeStatus` permissions (among others). Prior to versions 4.9.0 and 5.4.0, Kirby checked these permissions independently and only for the respective action. However the `changeStatus` permission didn't take effect on page creation. New pages are created as drafts by default and need to be published by changing the page status of an existing page draft. This is ensured when the page is created via the Kirby Panel. However the REST API allows to override the `isDraft` flag when creating a new page. This allowed authenticated attackers with the `pages.create` permission to immediately create published pages, bypassing the normal editorial workflow. The problem has been patched in Kirby 4.9.0 and Kirby 5.4.0. Kirby has added a check to the page creation rules that ensures that users without the `pages.changeStatus` permission cannot create published pages, only page drafts.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-40099 since 04/09/2026. The exploitation appears to be easy. The attack can be initiated remotely. There are neither technical details nor an exploit publicly available.

Upgrading to version 4.9.0 or 5.4.0 eliminates this vulnerability. The upgrade is hosted for download at github.com.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-25370). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Vendor

• getkirby

Name

• kirby

Version

• 4.0
• 4.1
• 4.2
• 4.3
• 4.4
• 4.5
• 4.6
• 4.7
• 4.8
• 5.0
• 5.1
• 5.2
• 5.3

Website

• Product: https://github.com/getkirby/kirby/

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

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