Kirby is an open-source content management system. Prior to 4.9.4 and 5.4.4, Kirby sites with content.fileRedirects enabled could redirect unauthenticated clean file URL requests for files stored in top-level draft pages to physical media URLs without checking page access permissions or preview tokens, leading to disclosure of draft file contents. This defect is a missing authorization weakness (CWE-862). This issue is fixed in versions 4.9.4 and 5.4.4.

The issue affects installations of getkirby Kirby CMS version 4 prior to 4.9.4 and version 5 prior to 5.4.4. Any site running those releases with the content.fileRedirects option enabled is vulnerable, regardless of other security controls.

The CVSS score of 6.3 denotes moderate severity, while the EPSS score of less than 1 % reflects a low current exploitation probability. The vulnerability is not listed in CISA’s KEV catalog. Exploitation requires only an unauthenticated HTTP request to a clean file URL that matches a draft file, leading to a redirect to the physical file location. An attacker can therefore obtain draft file contents without authentication, achieving information disclosure.