CVE-2026-43874 json
WWBN AVideo: Incomplete Fix for YPTSocket autoEvalCodeOnHTML Strip: Unauthenticated Cross-User JavaScript Execution via `$msg['json']` Relay Bypass
published 2026-05-05 6 mo ago modified 2026-10-26 13 d ago also GHSA-ghcv-22jf-vfxm , EUVD-2026-29310
- cvss
- 7.2
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 22%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 5 mo ago
Exploit prediction
0.29% chance of exploitation in the next 30 days, higher than 22% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/WWBN/AVideo/security/advisories/GHSA-ghcv-22jf-vfxm referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N |
| GitHub | 3.1 | 7.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| packagist | wwbn/avideo | <=29.0 |
no fix listed |
Affected products
- WWBN AVideo
Classification
- Weakness
-
- CWE-94 Improper Control of Generation of Code
References
Sources
- CVE List CVE-2026-43874
- GitHub Advisory GHSA-ghcv-22jf-vfxm
- NVD CVE-2026-43874
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