Cursor is a code editor built for programming with AI. In versions 1.7 and below, when MCP uses OAuth authentication with an untrusted MCP server, an attacker can impersonate a malicious MCP server and return crafted, maliciously injected commands during the interaction process, leading to command injection and potential remote code execution. If chained with an untrusted MCP service via OAuth, this command injection vulnerability could allow arbitrary code execution on the host by the agent. This can then be used to directly compromise the system by executing malicious commands with full user privileges. This issue does not currently have a fixed release version, but there is a patch, 2025.09.17-25b418f.
Cursor is a code editor built for programming with AI. In versions 1.6 and below, Mermaid (a to render diagrams) allows embedding images which then get rendered by Cursor in the chat box. An attacker can use this to exfiltrate sensitive information to a third-party attacker controlled server through an image fetch after successfully performing a prompt injection. A malicious model (or hallucination/backdoor) might also trigger this exploit at will. This issue requires prompt injection from malicious data (web, image upload, source code) in order to exploit. In that case, it can send sensitive information to an attacker-controlled external server. Some additional bypasses not covered in the initial fix to this issue were discovered, see GHSA-43wj-mwcc-x93p. This issue is fixed in version 1.7.