Amazon Q Developer Flaw Could Let Malicious Repos Run Code via MCP Configs

A high-severity issue in Amazon Q Developer could allow a malicious repository to trigger command execution and potentially steal developers’ cloud credentials through Model Context Protocol (MCP) server settings. The vulnerability is tracked as CVE-2026-12957 (CVSS 8.5) and affects the Language Servers for AWS component used by Amazon Q across VS Code, JetBrains, Eclipse, and Visual Studio, where repo-bundled MCP configuration could lead to running attacker-defined servers in the developer’s environment. This matters because it can turn trusted code checkout into unauthorized access to AWS identity and sensitive credentials unless systems are updated with the vendor’s fix.