CVE-2026-18953 - Improper limitation of a pathname in AWS Transform MCP Server

Bulletin ID: 2026-075-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 08/05/2026 12:30 PM PDT Description: The AWS Transform MCP Server (awslabs.aws-transform-mcp-server) is an open-source Model Context Protocol (MCP) server that runs locally on a developer's machine and lets AI-powered assistants interact with AWS Transform to run code-transformation jobs and retrieve their artifacts. We identified CVE-2026-18953. Improper limitation of a pathname to a restricted directory in the get_resource tool in awslabs.aws-transform-mcp-server before 0.1.5 might allow a context-dependent actor to write arbitrary files outside the intended working directory via the savePath parameter, which could lead to local code execution. Impacted versions: >=0.1.0 AND <=0.1.4 Please refer to the article below for the most up-to-date and complete information related to this AWS Security Bulletin.