blueprintUE Self-Hosted Edition before 4.3.6 contains an iframe injection vulnerability that allows authenticated users to embed arbitrary third-party content by abusing the PeerTube video URL matcher in BlueprintService::findVideoProvider(). Attackers can set a blueprint video URL on an attacker-controlled host, which site.js loads in an unsandboxed iframe after consent, framing fake login forms or malware downloads.
CWE-829