CVE-2026-54263: Wagtail: Reflected XSS in dynamic image URL generator view

A reflected cross-site scripting (XSS) vulnerability exists on the dynamic image URL generator view within the Wagtail admin interface. A user with a limited-permission editor account for the Wagtail admin could craft a URL that, when viewed by a user with higher privileges, could perform actions with that user’s credentials. The vulnerability is present for all sites, even if they do not enable the dynamic image serve view. The vulnerability is not exploitable by an ordinary site visitor without access to the Wagtail admin.