# 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.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:N`)
- **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 available:** No
- **Published:** 5 Aug 2026
- **Updated:** 10 Aug 2026
- **Also known as:** GHSA-pf4v-rpp4-fp6r

## 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 (Improper Neutralization of Input During Web Page Generation)

## 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.

## Is CVE-2026-71285 being exploited?

There is no known exploitation of CVE-2026-71285 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-71285 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-71285 in the wild and no public exploit code.

Affected product: louislam uptime-kuma. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-71285/ (Markdown: https://insights.sbomify.com/CVE-2026-71285/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-71285
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-71285
- OSV: https://osv.dev/vulnerability/CVE-2026-71285

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-71285/
Summaries are generated and may contain mistakes; the official description above is the record.