CVE-2026-58057

Flowise - Custom MCP Environment Variable Denylist Bypass via Case Sensitivity

Published Jun 28, 2026 CVSS 4.0 · 2.3 Low EPSS 1.6% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title Flowise - Custom MCP Environment Variable Denylist Bypass via Case Sensitivity
First Time appeared Flowiseai
Flowiseai flowise
Weaknesses CWE-178
CPEs cpe:2.3:a:flowiseai:flowise:*:*:*:*:*:*:*:*
Vendors & Products Flowiseai
Flowiseai flowise
References
Metrics cvssV3_1

{'score': 5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L'}

cvssV4_0

{'score': 2.3, 'vector': '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Nov 8, 2026, 2:06 PM
Reserved
Jun 28, 2026, 12:55 AM
Status
Analyzed
Published
Jun 28, 2026, 2:16 AM
Modified
Oct 25, 2026, 5:10 PM