{"id":"CVE-2026-40911","summary":"WWBN AVideo YPTSocket WebSocket Broadcast Relay Leads to Unauthenticated Cross-User JavaScript Execution via Client-Side eval() Sinks","details":"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.","aliases":["GHSA-gph2-j4c9-vhhr"],"modified":"2026-08-05T03:47:16.010910741Z","published":"2026-04-21T19:55:37.195Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-94"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40911.json","unresolved_ranges":[{"extracted_events":[{"last_affected":"29.0"}],"source":"AFFECTED_FIELD"}]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40911.json"},{"type":"ADVISORY","url":"https://github.com/WWBN/AVideo/security/advisories/GHSA-gph2-j4c9-vhhr"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-40911"},{"type":"FIX","url":"https://github.com/WWBN/AVideo/commit/c08694bf6264eb4decceb78c711baee2609b4efd"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/wwbn/avideo","events":[{"introduced":"0"},{"fixed":"c08694bf6264eb4decceb78c711baee2609b4efd"}],"database_specific":{"source":"REFERENCES"}}],"versions":["29.0","26.0","25.0","24.0","22.0","21.0","18.0","14.3.1","14.3","12.4","11.6","11.5","11.1.1","11.1","11","10.8","8.9.1","8.9","8.7","8.6","8.5","8.1","7.8","7.7","7.6","7.4","7.3","7.2","4.0","3.4","2.7","2.2"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-40911.json"}}],"schema_version":"1.8.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H"}]}