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Standard
Vulnerability Identifier

CVE-2026-40911

2026-04-21
Severity Assessment
10.0
CRITICAL
CVSS v3.x Score
Clinical Analysis (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.

Vector Sequencing

Attack Parameters

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Impact Consequences

Technical Impact

Changed
Scope
High
Confidentiality
High
Integrity
High
Availability
AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Weakness Classification

CWE-CWE-94

Timeline

Time Line

PUBLICATION
21 Apr 2026
Impact Statistics

Key Metrics

CVSS Score
10.0
CRITICAL
Remediation Protocol

Recommended Solution

No automatic solution found. Check vendor references.
Patch Library
No direct patch listed in database.
Recommended Actions for Administrators

Immediate Action Plan

1. Inventory

Identify all affected systems in your infrastructure.

2. Assessment

Assess exposure and criticality for your organization.

3. Mitigation

Apply patches or available workarounds.

4. Verification

Test and confirm effectiveness of applied measures.

⚠️ MAXIMUM PRIORITY - Immediate action required