Malicious website can execute commands on the local system through XSS in the OpenCode web UI
OpenCode is an open source AI coding agent. The markdown renderer used for LLM responses will insert arbitrary HTML into the DOM. There is no sanitization with DOMPurify or even a CSP on the web interface to prevent JavaScript execution via HTML injection. This means controlling the LLM response for a chat session gets JavaScript execution on the http://localhost:4096 origin. This vulnerability is fixed in 1.1.10.
High · CVSS 8.8EPSS 16.54%Public exploitFix available
OpenCode's Unauthenticated HTTP Server Allows Arbitrary Command Execution
OpenCode is an open source AI coding agent. Prior to 1.0.216, OpenCode automatically starts an unauthenticated HTTP server that allows any local process (or any website via permissive CORS) to execute arbitrary shell commands with the user's privileges. This vulnerability is fixed in 1.0.216.