CVE-2026-73601
Flowise before 3.1.3 Remote Code Execution via Custom MCP
Description
Flowise versions before 3.1.3 contain a remote code execution vulnerability in the Custom MCP node when CUSTOM_MCP_PROTOCOL is set to stdio, allowing authenticated users to execute arbitrary commands by manipulating environment variables and command arguments. Attackers can abuse PYTHONWARNINGS and BROWSER environment variables with python3, or leverage the root working directory with node to bypass validation and execute system commands.
INFO
Published Date :
Aug. 13, 2026, 12:17 p.m.
Last Modified :
Aug. 13, 2026, 12:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | CRITICAL | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | CRITICAL | [email protected] |
Solution
- Update Flowise to version 3.1.3 or later.
- Ensure CUSTOM_MCP_PROTOCOL is not set to stdio.
- Restrict access to the Custom MCP node.
- Validate environment variables and arguments.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-73601.
| URL | Resource |
|---|---|
| https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-g98q-rm45-q9h8 | |
| https://www.vulncheck.com/advisories/flowise-before-remote-code-execution-via-custom-mcp |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-73601 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-73601
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-73601 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-73601 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Aug. 13, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'FlowiseAI', 'product': 'Flowise', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '3.1.3', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '3.1.3', 'versionType': 'semver'}], 'packageURL': 'pkg:npm/flowise', 'defaultStatus': 'unaffected'}, {'vendor': 'FlowiseAI', 'product': 'Flowise', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '3.1.3', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '3.1.3', 'versionType': 'semver'}], 'packageURL': 'pkg:npm/flowise-components', 'defaultStatus': 'unaffected'}] Added Description Flowise versions before 3.1.3 contain a remote code execution vulnerability in the Custom MCP node when CUSTOM_MCP_PROTOCOL is set to stdio, allowing authenticated users to execute arbitrary commands by manipulating environment variables and command arguments. Attackers can abuse PYTHONWARNINGS and BROWSER environment variables with python3, or leverage the root working directory with node to bypass validation and execute system commands. Added CVSS V4.0 AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-95 Added Reference https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-g98q-rm45-q9h8 Added Reference https://www.vulncheck.com/advisories/flowise-before-remote-code-execution-via-custom-mcp