CVE-2026-30618

EUVD-2026-44845

15.07.2026, 22:16

xszyou Fay 4.3.1 contains a remote code execution vulnerability in its MCP STDIO server management and command execution handling. A remote attacker can access the publicly exposed MCP management interface and configure an MCP STDIO server with attacker-controlled commands and parameters, resulting in execution of arbitrary commands on the server. Successful exploitation allows arbitrary command execution within the context of the Fay service.

Code Injection

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	Primary	9.8 CRITICAL	NETWORK	LOW	NONE	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Awaiting analysis

This vulnerability is currently awaiting analysis.

Base Score

CVSS 3.x

EPSS Score

Percentile: 65.76%

Common Weakness Enumeration

CWE-94 - Improper Control of Generation of Code ('Code Injection')
The software constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.

References

https://github.com/xszyou/Fay

https://www.ox.security/blog/mcp-supply-chain-advisory-rce-vulnerabilities-across-the-ai-ecosystem/