Composer/Getkirby/Cms >= 5.0.0-Alpha.1, <= 5.4.3

Kirby CMS versions prior to 4.9.4 and between 5.0.0-alpha.1 and 5.4.3 are vulnerable to a self-cross-site scripting (self-XSS) flaw, CVE-2026-49276, in the writer field, allowing an attacker to inject malicious JavaScript as the target of a link or email link which, if clicked by an authenticated user before saving, will execute in their browser context, potentially making API requests with their permissions, while Panel plugins using the `<k-writer>` component may be vulnerable to stored XSS if they don't sanitize HTML.