CVE-2026-44175

Description

Kirby is an open-source content management system. In versions prior to 4.9.1 and 5.4.1, Kirby did not securely sanitize the contents of the list field on save, leaving it vulnerable to cross-site scripting (XSS). Kirby-s list field stores its formatted content as HTML, and unlike other field types, its HTML special characters cannot be escaped without losing the formatting. Sanitization was only enforced client-side in the Panel, while the server did not sanitize the content on save. As a result, an attacker could bypass the Panel and send malicious HTML directly to Kirby-s API, storing unsanitized markup in the content file. That markup would then be rendered on the site frontend and executed in the browsers of site visitors and logged-in users browsing the site, resulting in persistent XSS. This issue has been fixed in versions 4.9.1 and 5.4.1.