Vulnerability · Published Apr 20, 2026 · Assigned by VulDB
CVE-2026-6599langflow-ai langflow Model Context Protocol Configuration API mcp_projects.py install_mcp_config injection
Medium 6.3
In plain English
A medium-severity injection in langflow from langflow-ai. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 14% of all known vulnerabilities).
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | langflow | no fix listed | GHSA-v66p-f7x3-4794 |
| PyPI | langflow | no fix listed | PYSEC-2026-2569 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| langflow-ai | langflow | 1.8.01.8.11.8.21.8.3 |
Weakness: CWE-74, CWE-707 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:P/RL:W/RC:R
References
- VDB-358234 | langflow-ai langflow Model Context Protocol Configuration API mcp_projects.py install_mcp_config injection vdb-entry, technical-description
- VDB-358234 | CTI Indicators (IOB, IOC, TTP, IOA) signature, permissions-required
- Submit #791922 | Langflow <= 1.8.3 Authentication Bypass by Spoofing third-party-advisory
- https://gist.github.com/chenhouser2025/a909c47316b7a0948ee68c109ab747a3 exploit