CVE-2026-71285: Louislam Uptime-Kuma

High severity, CVSS 8.1. EPSS: 0.4% chance of exploitation in the next 30 days.

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 <script> 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/<slug> page, enabling session-cookie theft and full page takeover.

Affected products

• Louislam Uptime-Kuma: up to and including 2.4.0

Published 2026-08-05. Last modified 2026-08-26.