CVE-2026-58057
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.
Does this matter?
Lower severity and a low EPSS score (1.56%). Track it; it rarely justifies an emergency change on its own.
Description
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.
- CVSS 4.0
- 2.3 LOWCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 1.56% probability · 74th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-178
- Affected
- flowiseai/flowise
- Source
- disclosure@vulncheck.com
References
- https://github.com/FlowiseAI/Flowise/pull/6471Issue Tracking, Patch
- https://github.com/bikini/exploitarium/tree/main/flowise-mcp-env-case-bypass-pocExploit, Third Party Advisory
- https://www.vulncheck.com/advisories/flowise-custom-mcp-environment-variable-denylist-bypass-via-case-sensitivityExploit, Patch, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.