CVE-2026-58057
Flowise - Custom MCP Environment Variable Denylist Bypass via Case Sensitivity
- State
- Published
- Severity
- 2.3 Low
- Published
- Jun 28, 2026
- Updated
- Jun 29, 2026
- Reserved
- Jun 28, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 2.3 Low | 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 | VulnCheck |
| 3.1 | 5.0 Medium | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L | VulnCheck |
Weaknesses
- CWE-178 Improper Handling of Case Sensitivity
Affected Products
| Product | Versions |
|---|---|
FlowiseFlowise |
|
References
- Proof of Conceptexploitthird-party-advisory
- Fix (PR #6471, 3.1.3)issue-tracking
- VulnCheck Advisory: Flowise - Custom MCP Environment Variable Denylist Bypass via Case Sensitivitythird-party-advisory
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