Flowise - Custom MCP Environment Variable Denylist Bypass via Case Sensitivity
28Vexday Risk Score
No sign of exploitation. It has a public proof of concept.
ssvc Attendcvss 2.3epss 1.3%
from disclosure to weapon9 days
Published on NVDJun 28
1st PoC+9d
exploitation probability
1.3%top 33% of all CVEs
observed exploitation
nono source reports it
3 public exploit(s)
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 — 3
exploitdbwww.exploit-db.com/exploits/52623unverifiedgithubgithub.com/CerberusMrXi/Flowise-CVE-2026-58057-exploit★ 1cve_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.