CVE-2026-126814

Description

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.

References

• https://github.com/blueprintue/blueprintue-self-hosted-edition/blob/v4.3.5/app/services/www/BlueprintService.php#L700-L716
• https://github.com/blueprintue/blueprintue-self-hosted-edition/commit/5f13e2bb8cd4c620899e9f8afd41a6e62b3bc6a4
• https://github.com/blueprintue/blueprintue-self-hosted-edition/pull/269
• https://github.com/blueprintue/blueprintue-self-hosted-edition/releases/tag/v4.3.6
• https://github.com/blueprintue/blueprintue-self-hosted-edition/security/advisories/GHSA-3vgc-fcfg-v233