CVE-2026-40911
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedWWBN 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe YPTSocket plugin in AVideo versions 29.0 and prior contains a critical vulnerability where its WebSocket server relays unsanitized attacker-controlled JSON data (specifically the `msg` and `callback` fields) to all connected clients. Two `eval()` sinks in the client-side script.js (lines 95 and 568) execute code from these relayed fields without validation, allowing unauthenticated attackers to inject arbitrary JavaScript that executes in every connected user's browser origin.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data<= 29.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify AVideo installation and versionCheck your web server for AVideo by looking for the main index.php file and examine the version number in the software documentation or version file (often in a version.php or similar file in the root directory)Affected if The installed AVideo version is 29.0 or any version prior to 29.0
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Locate and verify the YPTSocket pluginCheck the plugin directory (typically /plugin/YPTSocket/) in your AVideo installation to see if the YPTSocket plugin directory exists and contains plugin filesAffected if The YPTSocket plugin is present in the plugins directory
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Verify if YPTSocket is enabledCheck the AVideo database or plugin configuration file for the YPTSocket plugin status - look for enable/disable settings in the plugin configuration or database tableAffected if The YPTSocket plugin is enabled in the AVideo configuration
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Identify if WebSocket server is runningCheck if the YPTSocket WebSocket server process is running - look for the YPTSocket server listening on its configured port (check plugin configuration for port number)Affected if The YPTSocket WebSocket server is active and accepting connections
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Inspect script.js for vulnerable eval() callsLocate the client-side script.js file in the YPTSocket plugin directory (or loaded by it) and examine lines around 95 and 568 for eval() calls that process WebSocket message data without sanitizationAffected if The script.js file contains eval() statements that execute data from WebSocket msg or callback fields without validation
A user is affected if running AVideo version 29.0 or earlier with the YPTSocket plugin enabled and its WebSocket server active, where the client-side script.js contains unsanitized eval() calls on WebSocket message data.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade AVideo to a version containing commit c08694bf6264eb4decceb78c711baee2609b4efd or disable the YPTSocket plugin until patching is possible.
AVideo version 29.1 or later (commit after c08694bf6264eb4decceb78c711baee2609b4efd)
- 1. Identify the AVideo installation directory on the server
- 2. Navigate to the GitHub repository for AVideo (github.com/WWBN/AVideo)
- 3. Check the commit c08694bf6264eb4decceb78c711baee2609b4efd to identify the fixed version
- 4. Backup the current AVideo installation and database before upgrading
- 5. Upgrade AVideo to the version containing the fix (version 29.1 or later, or the commit after c08694bf)
- 6. Verify the YPTSocket plugin has been updated by checking plugin/YPTSocket/script.js no longer contains eval() calls on lines 95 and 568
- 7. Restart any relevant services if required
- 8. Test WebSocket functionality to ensure the platform still operates correctly
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,408.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-40911 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-40911 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data