CVE-2026-43874

CVE-2026-43874 · WWBN AVideo: Incomplete Fix for YPTSocket autoEvalCodeOnHTML Strip: Unauthenticated Cross-User JavaScript Execution via `$msg['json']` Relay Bypass

This page contains facts from public vulnerability sources. Check the original advisory before updating.

WWBN AVideo is an open source video platform. In versions up to and including 29.0, the server-side mitigation for the YPTSocket autoEvalCodeOnHTML eval sink (from CVE-2026-40911) only strips the payload when it sits under $json['msg'], but the relay function msgToResourceId() selects the outbound message from $msg['json'] before $msg['msg']. An unauthenticated attacker can obtain a WebSocket token from plugin/YPTSocket/getWebSocket.json.php, connect to the WebSocket server, and send a message with autoEvalCodeOnHTML nested under a top-level json field — the strip branch is skipped, the relay delivers the payload verbatim to any logged-in user identified by to_users_id, and the client script runs it through eval(). Commit 9f3006f9a89a34daa67a83c6ad35f450cb91fcce contains an updated fix.

CVSS 7.2 · High · EPSS 0.3%

Published

2026-05-11T20:29:59.468Z

Updated

2026-05-12T13:24:03.400Z

Stack: php

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