CVE-2026-39370: WWBN AVideo has an Allowlisted downloadURL media extensions bypass SSRF protection and enable internal response exfiltration (Incomplete fix for CVE-2026-27732)

WWBN AVideo is an open source video platform. In versions 26.0 and prior, objects/aVideoEncoder.json.php still allows attacker-controlled downloadURL values with common media or archive extensions such as .mp4, .mp3, .zip, .jpg, .png, .gif, and .webm to bypass SSRF validation. The server then fetches the response and stores it as media content. This allows an authenticated uploader to turn the upload-by-URL flow into a reliable SSRF response-exfiltration primitive. The vulnerability is caused by an incomplete fix for CVE-2026-27732.