The vulnerability in Upsonic 0.71.6 arises from insufficient restriction on command arguments in the MCP server/task creation feature. While an allowlist restricts which commands can be run, commands like npm and npx still allow argument flags that enable arbitrary OS command execution. This flaw permits attackers to craft malicious MCP tasks that execute code remotely with the same privileges as the Upsonic process. The vendor has acknowledged the risk by adding a warning in version 0.72.0 but has not provided an official fix or patch as of the published date.

Successful exploitation of this vulnerability allows remote attackers to execute arbitrary code on the affected system with the privileges of the Upsonic process. This could lead to full system compromise depending on the privileges of the Upsonic process. There are no known exploits in the wild at this time.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. The vendor has added a warning in version 0.72.0 about the risks of using Stdio servers that can execute commands directly. Until an official fix is available, users should avoid using MCP tasks with commands that accept argument flags capable of arbitrary code execution, such as npm and npx, or restrict access to the MCP server functionality to trusted users only.