What’s Vulnerable › Vulnerabilities

CVE-2026-40911: WWBN AVideo YPTSocket WebSocket Broadcast Relay Leads to Unauthenticated Cross-User JavaScript Execution via Client-Side eval() Sinks

• Severity: critical (CVSS 10.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-04-21 · updated 2026-10-26
• Weakness: CWE-94

Description

WWBN AVideo is an open source video platform. In versions 29.0 and prior, the YPTSocket plugin's WebSocket server relays attacker-supplied JSON message bodies to every connected client without sanitizing the `msg` or `callback` fields. On the client side, `plugin/YPTSocket/script.js` contains two `eval()` sinks fed directly by those relayed fields (`json.msg.autoEvalCodeOnHTML` at line 568 and `json.callback` at line 95). Because tokens are minted for anonymous visitors and never revalidated beyond decryption, an unauthenticated attacker can broadcast arbitrary JavaScript that executes in the origin of every currently-connected user (including administrators), resulting in universal account takeover, session theft, and privileged action execution. Commit c08694bf6264eb4decceb78c711baee2609b4efd contains a fix.

Affected products

• WWBN AVideo: through 29.0

References

• https://github.com/WWBN/AVideo/commit/c08694bf6264eb4decceb78c711baee2609b4efd
• https://github.com/WWBN/AVideo/security/advisories/GHSA-gph2-j4c9-vhhr
• https://github.com/WWBN/AVideo/security/advisories/GHSA-gph2-j4c9-vhhr

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