PySyft (Syft Datasite/Server) versions 0.9.5 and earlier permit low‑privileged users to submit Python functions through the @sy.syft_function decorator for execution on the server. The submitted code passes through an approval mechanism that performs no security checks; once approved it is executed via exec() and eval() within the server process. This allows an attacker to run arbitrary Python code, giving full control and leading to a complete compromise of the server environment.

Python library PySyft (Syft Datasite/Server), versions 0.9.5 and earlier.

The vulnerability is a classic remote code execution flaw (CWE‑94). The EPSS score is < 1%, the CVSS score is 9.8, and the CVE is not listed in CISA KEV. Because the code is run inside the server process with full privileges, the exploitation would grant an attacker complete control over the server, threatening confidentiality, integrity, and availability. The most likely attack vector is via legitimate user functions submitted through the standard interface; any user who can create or update a function has the potential to trigger the flaw.