CVE-2026-58057
Flowise - Custom MCP Environment Variable Denylist Bypass via Case Sensitivity
Vexday Risk Score
28Low
SSVC decision (CISA)
Attend
PoC available → attend closely
CVSS 2.3EPSS 0.2%KEV nãoPoC públicaNuclei —Metasploit —Patch —
Lifecycle
28 Jun 2026Published on NVD
Recommendation: Plan a near-term fix — a public PoC already exists.
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/AV:N/AC:H/AT:P/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N
Affected products
Flowise · Flowisepublic PoCs found — 1
cve_referencegithub.com/bikini/exploitarium/tree/main/flowise-mcp-env-case-bypass-pocunverified⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.