CVE-2026-56274
HIGH EPSS 83.9%
Published Jun 23, 20261w ago · Modified Jun 24, 20266d ago
8.7 CVSS 4.0
Published Jun 23, 2026 1w ago
Last Modified Jun 24, 2026 6d ago
Description
Flowise before 3.1.2 contains multiple OS command injection vulnerabilities in the Custom MCP Server feature due to incomplete command-flag validation and a regex bypass in local file access restrictions. An attacker with a Flowise account of any role, or API access with view/update permissions for chatflows, can configure a malicious MCP server to bypass the validateCommandFlags blocklist (for example, 'docker build' is not blocked, and 'npx --yes' is not blocked while only '-y' is) and the validateArgsForLocalFileAccess checks, resulting in execution of arbitrary commands on the Flowise host.
CVSS Details
Base Score
Exploitability
Impact
Vector string
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/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 Attack Vector Network
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope X
Threat Intelligence
EPSS Exploit Probability
83.9% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available
Weaknesses 1
CWE-78 OS Command Injection Injection
References 2
- github.com https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-m99r-2hxc-cp3q
- vulncheck.com https://www.vulncheck.com/advisories/flowise-remote-code-execution-via-mcp-security-bypass-in-validatecommandflags-and-validateargsforlocalfileaccess
Remediation
No remediation data recorded yet
Check vendor advisories and the NVD entry for patch availability.