Vulnerability Report

CVE-2026-58057

RCE

Title: Case-insensitive Denylist Bypass in Flowise leads to RCE

RCE

Proof Of Concept

PoC Available for CVE-2026-58057

CWE Category CWE-178
Published Date Jun 28, 2026
Modified Date Jul 06, 2026
Exploit Status Available
Score 2.3 CVSS v4.0
Exploit Probability (EPSS)
1.27%

Vulnerability Summary

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.

Impacted Vendors

F
flowiseai 1

Reference Links

https://github.com/FlowiseAI/Flowise/pull/6471 https://github.com/bikini/exploitarium/tree/main/flowise-mcp-env-case-bypass-poc https://www.vulncheck.com/advisories/flowise-custom-mcp-environment-variable-denylist-bypass-via-case-sensitivity
CVSS v4.0
Source Entity [email protected]
Severity LOW
2.3
Attack Vector
NETWORK
Complexity
HIGH
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
N/A
RAW 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS v3.1
Source Entity [email protected]
Severity MEDIUM
5.0
Attack Vector
NETWORK
Complexity
HIGH
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-58057 Exploits & PoCs (Proof Of Concept)

Exploit-DB https://www.exploit-db.com/exploits/52623
View Code
MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity HIGH
Privileges N/A
Interaction NONE
CVSS Vector String 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected Stack

No specific products linked.