CVE-2026-55529

PraisonAI (a multi-agent teams system) has an origin validation bypass in its MCP HTTP Stream transport. The _validate_origin method uses request_origin.startswith(allowed), so an attacker-controlled origin like http://localhost.evil.example matches the http://localhost allowlist entry via prefix...

PraisonAI has an origin validation bypass in MCP HTTP Stream transport that allows browser-mediated unauthenticated tool execution on local MCP server

Summary PraisonAI's MCP HTTP Stream transport uses an unsafe prefix match when validating the Origin header. The default localhost allowlist includes origins such as http://localhost, and the validation accepts any origin that starts with an allowed value. As a result, an attacker-controlled orig...