Vulnerability in Flowise
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. 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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.0 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.016 (74.2th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 74th percentile — 74.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.016 · newest: 0.016 · change: 0.000
Affected products
- Flowise — versions 0, 3.1.3
- Flowiseai Flowise
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/FlowiseAI/Flowise/pull/6471 (issue-tracking, Patch, Issue Tracking)
- github.com/bikini/exploitarium/tree/main/flowise-mcp-env-case-bypass-poc (Exploit, Third Party Advisory, exploit, third-party-advisory)
- www.vulncheck.com/advisories/flowise-custom-mcp-environment-variable-denylist-b… (Exploit, Patch, Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-58057?
- CVE-2026-58057 is a medium-severity vulnerability in Flowise, classified under Improper Handling of Case Sensitivity. CVSS score: 5.0/10. Published 2026-06-28.
- How severe is CVE-2026-58057?
- Medium severity. CVSS v3 base score is 5.0 out of 10.
- Is CVE-2026-58057 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.