CVE-2026-71285

Uptime Kuma's Matomo analytics integration (server/analytics/matomo-analytics.js) injects the admin-configurable Matomo value as a bare, unquoted JavaScript expression inside a block rendered on every public status page. A siteId value such as , once saved by an editor/admin, executes arbitrary JavaScript for every unauthenticated visitor of the public /status/ page, enabling session-cookie theft and full page takeover.