CVE-2026-49276

In Kirby CMS versions prior to 4.9.1 and 5.4.1, a vulnerability was found where URL methods for KirbyTags and image blocks components did not filter malicious URL values that resolve to script execution. Attackers can use URL formats like `javascript://x%0A…` to bypass protection against simple `javascript:` URLs and execute scripts.

In Kirby CMS versions prior to 4.9.1 and 5.4.1, the content-locking feature exposed user email addresses and identifiers without checking access permissions. A low-privilege authenticated user could learn the email and ID of any user currently editing a model, including administrators.

In Kirby CMS versions 5.3.0 through 5.4.0, a path traversal vulnerability was found due to improper validation of user IDs. An attacker could include arbitrary PHP files named index.php and probe the server's directory structure.

In Kirby CMS versions prior to 4.9.1 and 5.4.1, the `pages.access` permission was not checked during page draft rendering. An authenticated attacker with knowledge of the full path to an existing draft could access its frontend preview, leading to disclosure of sensitive information.

Kirby CMS versions prior to 4.9.1 and 5.4.1 do not properly sanitize the list field content on save, allowing XSS attacks. An attacker can bypass the Panel and send malicious HTML directly to the API, which will be executed in visitors' browsers.

Kirby CMS before versions 4.9.1 and 5.4.1 does not validate model attributes used in collection queries, allowing attackers to invoke arbitrary model methods. This can lead to disclosure of sensitive data (e.g., password hashes, filesystem paths) or execution of impactful actions (e.g., privilege escalation, mass deletion of models).

In Kirby CMS before versions 4.9.4 and 5.4.4, with content.fileRedirects enabled, unauthenticated clean file URL requests for files in top-level draft pages are redirected to physical media URLs without checking page access permissions or preview tokens, leading to disclosure of draft file contents.

A vulnerability in Kirby CMS before versions 4.9.4 and 5.4.4 allows stored cross-site scripting via malicious markup injected as children of unknown HTML/XML tags. The sanitization functions fail to properly filter such input.

A vulnerability in Kirby CMS allows HTTP header injection via newline characters in the header value of the headers option in the Http Remote class. An attacker can inject an unintended header into outgoing requests.

A vulnerability in the Kirby content management system allows authenticated users with the pages.access permission disabled to confirm the existence of inaccessible pages and retrieve their titles via the pages field. The issue is fixed in versions 4.9.4 and 5.4.4.