CVE-2026-88871: WWBN AVideo CustomizeUser setSubscribers CSRF via GET
WWBN AVideo through commit c3edcc274c389816d434acadac07ee78eaf330c1 (master, 2026-08-23) contains a cross-site request forgery vulnerability in the CustomizeUser plugin's plugin/CustomizeUser/setSubscribers.json.php endpoint. The script reads usersid and ExtraSubscribers from $REQUEST and calls User::setExtraSubscribers() without requiring a POST request or a valid CSRF token; autoCSRFGuard() is applied only to POST requests to .json.php, and the mutation does not pass through ObjectYPT::save()/isUntrustedRequest(), so a cross-origin GET succeeds. An unauthenticated remote attacker who induces a logged-in administrator to load a crafted page (for example an <img> tag pointing at the endpoint) can forge the ExtraSubscribers count displayed on any user's channel. The CustomizeUser plugin is enabled by default, and no patched version was available at the time of reporting.
Affected Software
Event History
Frequently Asked Questions
Who is exposed to this issue?
Instances with the CustomizeUser plugin enabled are exposed; the plugin is enabled by default. Exploitation requires a logged-in administrator to be induced to load attacker-controlled content.
What does an attacker need to do to exploit it?
The attacker does not need to authenticate, but must cause a logged-in administrator’s browser to make a cross-origin GET request to the setSubscribers.json.php endpoint. A crafted page can trigger this request, for example through an image tag.
What can an attacker change?
An attacker can forge the ExtraSubscribers count displayed on any user’s channel. The supplied data does not indicate confidentiality impact, account takeover, or service disruption.
Is there a patch or configuration-based mitigation?
No patched version was available at the time of reporting. The data identifies the CustomizeUser plugin as the affected component, so disabling that plugin removes the default-enabled affected functionality if doing so is operationally acceptable.