CVE-2026-73601

critical · 9

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

1.1%

EPSS (exploit prob.)

64th

EPSS percentile

2026-08-13

Published

CVSS:4.0/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

Weaknesses

CWE-95

Affected products

Vendor	Product	Affected versions
flowiseai	flowise	< 3.1.3

Check a specific version with /api/v1/cve/match.

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

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-73601