PraisonAI is a multi-agent teams system. Prior to praisonai 4.6.58, Browser Server _handle_connection() checks Chrome extension origins with re.match() and the unanchored expression chrome-extension://[a-z0-9]{32}. Extra trailing characters pass before websocket.accept(), allowing start_session commands and unauthorized browser automation. This issue is fixed in version 4.6.58.

CVE-2026-55536 affects PraisonAI, a multi-agent teams system, in versions prior to 4.6.58. The vulnerability resides in the Browser Server's _handle_connection() function, which validates Chrome extension origins using Python's re.match() with an unanchored regular expression: chrome-extension://[a-z0-9]{32}. Because re.match() only matches from the start of the string without requiring a full match, extra trailing characters in the origin are not rejected, allowing the WebSocket connection to be accepted. This flaw enables attackers to send start_session commands and perform unauthorized browser automation. The vulnerability represents an improper input validation issue in the origin-checking logic. A fix was released in PraisonAI version 4.6.58, which addresses the regex anchoring problem. Users are advised to upgrade immediately to the patched version.