CVE-2026-121627

buku 5.0 through 5.1.1 contains a stored cross-site scripting vulnerability in the bukuserver bookmark list that allows attackers to execute script via an unescaped bookmark URL in BookmarkModelView._list_entry(). Attackers can submit a URL containing a double quote and event handler through the unauthenticated /api/bookmarks endpoint to issue same-origin API requests with viewers' credentials.