CVE-2026-73601: Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection') in FlowiseAI Flowise
Flowise versions before 3.1.3 have a remote code execution vulnerability in the Custom MCP node when CUSTOM_MCP_PROTOCOL is set to stdio. Authenticated users can exploit this by manipulating environment variables such as PYTHONWARNINGS and BROWSER with python3 or by leveraging the root working directory with node to bypass validation and execute arbitrary system commands.
AI Analysis
Technical Summary
CVE-2026-73601 describes an improper neutralization of directives in dynamically evaluated code (eval injection) vulnerability in FlowiseAI's Flowise product. Specifically, in versions prior to 3.1.3, the Custom MCP node configured with CUSTOM_MCP_PROTOCOL set to stdio allows authenticated users to execute arbitrary commands remotely. This is achieved by manipulating environment variables (PYTHONWARNINGS, BROWSER) when using python3 or by exploiting the root working directory with node to bypass validation controls, leading to remote code execution.
Potential Impact
Successful exploitation allows an authenticated user to execute arbitrary system commands remotely, potentially leading to full system compromise, data theft, or disruption of service. The vulnerability has a CVSS 4.0 score of 9, indicating critical severity with high impact on confidentiality, integrity, and availability.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict access to authenticated users only and monitor for suspicious activity related to environment variable manipulation in the Custom MCP node. Avoid setting CUSTOM_MCP_PROTOCOL to stdio if possible.
CVE-2026-73601: Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection') in FlowiseAI Flowise
Description
Flowise versions before 3.1.3 have a remote code execution vulnerability in the Custom MCP node when CUSTOM_MCP_PROTOCOL is set to stdio. Authenticated users can exploit this by manipulating environment variables such as PYTHONWARNINGS and BROWSER with python3 or by leveraging the root working directory with node to bypass validation and execute arbitrary system commands.
CVSS v4.0
Score 9.0critical
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-73601 describes an improper neutralization of directives in dynamically evaluated code (eval injection) vulnerability in FlowiseAI's Flowise product. Specifically, in versions prior to 3.1.3, the Custom MCP node configured with CUSTOM_MCP_PROTOCOL set to stdio allows authenticated users to execute arbitrary commands remotely. This is achieved by manipulating environment variables (PYTHONWARNINGS, BROWSER) when using python3 or by exploiting the root working directory with node to bypass validation controls, leading to remote code execution.
Potential Impact
Successful exploitation allows an authenticated user to execute arbitrary system commands remotely, potentially leading to full system compromise, data theft, or disruption of service. The vulnerability has a CVSS 4.0 score of 9, indicating critical severity with high impact on confidentiality, integrity, and availability.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict access to authenticated users only and monitor for suspicious activity related to environment variable manipulation in the Custom MCP node. Avoid setting CUSTOM_MCP_PROTOCOL to stdio if possible.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-08-13T11:15:12.095Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a7dbdf8bf8831d539322568
Added to database: 08/13/2026, 12:52:08 UTC
Last enriched: 08/13/2026, 12:53:56 UTC
Last updated: 08/13/2026, 14:51:02 UTC
Views: 4
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