CVE-2026-43876
WWBN AVideo is an open source video platform. In versions up to and including 29.0, objects/notifySubscribers.json.php takes the raw message POST parameter and passes it into sendSiteEmail(), which substitutes it directly into an HTML email template (via str_replace on the {message} placeholder) and renders it with PHPMailer::msgHTML(). There is no HTML sanitization, character escaping, or output encoding on the attacker-controlled message between $_POST['message'] and the rendered email.
Any authenticated user with upload permission can therefore broadcast arbitrary HTML, phishing links, tracking pixels, CSS/UI spoofing, to every subscriber on their channel (up to 10,000 recipients per invocation). The email is sent From: the platform's configured contact address and wrapped in the site's official logo and title, so attacker-supplied HTML arrives with the appearance of an official platform communication. Commit https://github.com/WWBN/AVideo/commit/ contains an updated fix.
- No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence
ATT&CK techniques
2Techniques this CVE enables - linked via CWECAPECATT&CK. High◆ = named directly in ATT&CK or Nuclei templates.
▤ Build a SIEM detection for these techniquesCAPEC attack patterns
6Attack patterns this CVE enables - the bridge from weakness to ATT&CK technique.