RCE Flaw in AI-Assisted Coding Tool Poses Software Supply Chain Risk

Check Point Research disclosed "MCPoison" (CVE-2025-54136), a critical flaw in Cursor's Model Context Protocol that lets an attacker silently modify approved MCP extensions to achieve persistent remote code execution and privilege escalation on developer machines (potentially exposing credentials and source code). The issue enables attackers with write access to a repository to embed reverse shells or arbitrary commands that execute whenever a project is opened or synced. Cursor released version 1.3 to enforce mandatory re-approval of any MCP changes and address this and the related "CurXecute" (CVE-2025-54135) prompt-injection flaw; organizations are advised to update immediately.