High severity · published May 11, 2026
CVE-2026-43874
WWBN AVideo: Incomplete Fix for YPTSocket autoEvalCodeOnHTML Strip: Unauthenticated Cross-User JavaScript Execution via `$msg['json']` Relay Bypass
7.2
CVSS
0.3%
EPSS
No
On KEV
Description
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 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 22% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AV
AVideo · WWBN
<= 29.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-43874
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-43874
github.com
https://github.com/WWBN/AVideo/commit/9f3006f9a89a34daa67a83c6ad35f450cb91fcce
github.com
https://github.com/WWBN/AVideo/security/advisories/GHSA-ghcv-22jf-vfxm
More from AVideo
10.0
CVE-2026-40911
WWBN AVideo YPTSocket WebSocket Broadcast Relay Leads to Unauthenticated Cross-User JavaScript Execution via Client-Side eval() Sinks
10.0
CVE-2026-33478
AVideo Multi-Chain Attack: Unauthenticated Remote Code Execution via Clone Key Disclosure, Database Dump, and Command Injection
9.9
CVE-2022-30547
A directory traversal vulnerability exists in the unzipDirectory functionality of WWBN AVideo 11.6 and dev master commit 3f7c0364
9.8
CVE-2026-86189
WWBN AVideo Unauthenticated Path Traversal via notify.ffmpeg.json.php
9.8
CVE-2026-85154
WWBN AVideo Authentication Bypass via Non-Expiring video_id_hash
