CVE-2026-43874 json
WWBN AVideo: Incomplete Fix for YPTSocket autoEvalCodeOnHTML Strip: Unauthenticated Cross-User JavaScript Execution via `$msg['json']` Relay Bypass
published 6mo ago modified 14d ago also EUVD-2026-29310 , GHSA-ghcv-22jf-vfxm
- 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
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Check with FencerCISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 5mo ago
Exploit prediction
0.29% chance of exploitation in the next 30 days, higher than 22% of all scored CVEs (FIRST EPSS, 2026-11-09).
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
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.