Critical (9.8). EPSS 1.2% chance of exploitation in the next 30 days.
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.
Severity
CVSS 3.1
9.8 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
1.2% chance of exploitation in the next 30 days; higher than 68% of CVEs (scores of 2026-10-31)