CVE-2026-58057

EUVD-2026-39977
Flowise before 3.1.3 validates Custom MCP stdio environment variables against a denylist using a case-sensitive comparison, so on Windows, where environment names are case-insensitive, supplying 'node_options' bypasses the NODE_OPTIONS denylist entry. An authenticated user who can configure a Custom MCP node can thereby inject NODE_OPTIONS --require and execute arbitrary code in the Flowise server context.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
5 MEDIUM
NETWORK
HIGH
LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L
Base Score
CVSS 3.x
EPSS Score
Percentile: 67.15%
Affected Products (NVD)
VendorProductVersion
flowiseaiflowise
𝑥
< 3.1.3
𝑥
= Vulnerable software versions
Common Weakness Enumeration
Vulnerability Media Exposure
References
https://github.com/FlowiseAI/Flowise/pull/6471
https://github.com/bikini/exploitarium/tree/main/flowise-mcp-env-case-bypass-poc
https://www.vulncheck.com/advisories/flowise-custom-mcp-environment-variable-denylist-bypass-via-case-sensitivity