CVE-2026-71285 Uptime Kuma Stored XSS via Matomo Analytics Site ID on Public Status Pages
Attackers can execute arbitrary JavaScript on public status pages via Matomo Site ID, stealing cookies and taking over sessions.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-71285?
CVE-2026-71285 is a high-severity cross-site scripting vulnerability in louislam uptime-kuma, published on 5 Aug 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-79
Which versions are affected by CVE-2026-71285?
How do I fix CVE-2026-71285?
No fix has been published for CVE-2026-71285 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-71285 being exploited?
There is no known exploitation of CVE-2026-71285 in the wild and no public exploit code.
Sources
Also known as GHSA-pf4v-rpp4-fp6r.