CVE-2026-73601

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.

CVSS 4.0

9.0CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

CVSS 3.1

8.8CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS

1.1% chance of exploitation in the next 30 days; higher than 65% of CVEs (scores of 2026-10-25)

CWE

CWE-95

Published

2026-08-13

Modified

2026-10-24

Record from

the NVD, synced 2026-10-24

Affected

• flowiseai:flowise

References

• https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-g98q-rm45-q9h8
• https://www.vulncheck.com/advisories/flowise-before-remote-code-execution-via-custom-mcp

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