# CVE-2026-89039: Arbitrary file read via the convert_playwright_script prompt in mcp-k6

> Attackers can read arbitrary files, including sensitive credentials, by exploiting path traversal in the convert_playwright_script prompt of mcp-k6.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 Oct 2026
- **Updated:** 5 Oct 2026
- **Also known as:** GHSA-ffg3-vfrj-4mjj

## What is CVE-2026-89039?

CVE-2026-89039 is a medium-severity path traversal vulnerability in Grafana mcp-k6, published on 5 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A caller who can invoke the convert_playwright_script prompt in mcp-k6 can pass a bare file path as the playwright_script argument and receive the contents of any file readable by the user running the server, including SSH keys and cloud credentials in that user's home directory (path traversal). The working-directory restriction applied to '@'-prefixed paths can also be bypassed with a symbolic link inside the working directory that points outside it.

Weakness: CWE-424 (Improper Protection of Alternate Path), CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-89039?


## How do I fix CVE-2026-89039?

No fix has been published for CVE-2026-89039 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-89039 being exploited?

There is no known exploitation of CVE-2026-89039 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89039 and fix it if it is affected.

What it is: CVE-2026-89039 is a medium-severity path traversal vulnerability in Grafana mcp-k6, published on 5 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-89039 in the wild and no public exploit code.

Affected product: Grafana mcp-k6. 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-2026-89039/ (Markdown: https://insights.sbomify.com/CVE-2026-89039/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89039
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89039
- OSV: https://osv.dev/vulnerability/CVE-2026-89039

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89039/
Summaries are generated and may contain mistakes; the official description above is the record.