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Critical · 9.8 CVE-2026-31220 EUVD-2026-29504GHSA-cfpg-c974-jfhqPYSEC-2026-546

PySyft server-side arbitrary Python execution after code approval

Published May 12, 2026 · Updated May 15, 2026 · Assigned by mitre

Description

PySyft (Syft Datasite/Server) versions 0.9.5 and earlier are vulnerable to remote code execution due to insufficient validation and sandboxing of user-submitted code. The system allows low-privileged users to submit Python functions (via @sy.syft_function()) for remote execution on the server. While a code approval mechanism exists, the submitted code undergoes no security checks for dangerous operations (e.g., file access, command execution). Once approved, the code is executed within the server process using exec() and eval() functions without proper isolation. A remote attacker can leverage this to execute arbitrary Python code on the server, leading to complete compromise of the server environment.

Affected packages

EcosystemPackageAffectedFixedRecord
PyPI syft <= 0.9.5 — GHSA-cfpg-c974-jfhq

References