Incomplete validation in the run_script Python sandbox in AWS MCP Server

Bulletin ID: 2026-149-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 10/23/2026 12:00 PM PDT Description: AWS MCP Server is a managed server that gives AI agents access to AWS through the Model Context Protocol (MCP), including a run_script tool that runs Python scripts in a sandboxed environment. We identified CVE-2026-115845, an issue in the Python code validator of the run_script tool in AWS MCP Server. An incomplete list of disallowed inputs might allow an authenticated remote user to execute arbitrary code within their own isolated session environment via a crafted script. Impacted versions: N/A (managed service, exclusively hosted) Please refer to the article below for the most up-to-date and complete information related to this AWS Security Bulletin. Read this article