CVE-2026-34587 Details
Description
Kirby is an open-source content management system. Prior to versions 4.9.0 and 5.4.0, 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). In affected releases, 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 updated the `Options` logic to no longer double-resolve queries in option values coming from `OptionsQuery` or `OptionsApi` sources. Kirby now only resolves queries that are directly configured in the blueprints.
A server-side template injection vulnerability has been identified in Kirby, an open-source content management system, in versions prior to 4.9.0 and 5.4.0. This vulnerability arises in sites using option fields such as checkboxes, color, multiselect, select, radio, tags, or toggles, with options sourced from untrusted queries or APIs. The issue allows authenticated attackers to inject malicious templates that could be executed in the Kirby Panel, potentially accessing or altering protected site information. The vulnerability is exacerbated by double resolution of dynamic option values, which could lead to unauthorized access or actions, especially if exploited by a user with higher permissions.
Users are advised to update to Kirby versions 4.9.0 or 5.4.0. Instructions for updating Kirby via Composer are available in the Kirby 5.4.0 release notes.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Apr 24, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/getkirby/kirby/releases/tag/4.9.0 | [email protected] | Release Notes |
| https://github.com/getkirby/kirby/releases/tag/5.4.0 | [email protected] | Release Notes |
| https://github.com/getkirby/kirby/security/advisories/GHSA-jcjw-58rv-c452 | [email protected] | PatchVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-1336 | Improper Neutralization of Special Elements Used in a Template Engine | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| getkirby kirby | < 4.9.0 >= 5.0.0, < 5.4.0 |
CPE
Remediation
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Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Apr 27, 2026 | Initial Analysis | [email protected] |
| Apr 24, 2026 | New CVE Received | [email protected] |