CVE-2026-43879: AVideo has Blind SSRF in YPTWallet Donation Webhook via Missing isSSRFSafeURL() Check and CURLOPT_FOLLOWLOCATION Redirect Bypass

An authenticated user can configure their own donation-notification webhook URL to point at internal/loopback/metadata hosts (e.g. http://127.0.0.1:8080/..., http://169.254.169.254/latest/..., RFC1918 addresses). When any other user (including a second account owned by the same attacker) donates even a trivial amount via plugin/CustomizeUser/donate.json.php, the AVideo server issues a curl POST to the attacker-supplied URL, resulting in a blind SSRF. The handler uses only isValidURL() (which is a format check) and does not call the codebase’s own isSSRFSafeURL() helper. Additionally, CURLOPT_FOLLOWLOCATION is enabled with no per-hop revalidation, so even if the stored URL were validated, an HTTP 307 from an attacker-controlled host could redirect the POST to internal targets.