CVE-2026-4357: Unknown Embed HTML5 Game

Critical severity, CVSS 10.0. EPSS: 0.5% chance of exploitation in the next 30 days.

The Embed HTML5 Game WordPress plugin through 1.3 does not properly restrict who can upload files via the plugin, as well as what can be uploaded, making it possible for unauthenticated attackers to upload PHP backdoors on affected sites.

Affected products

• Unknown Embed HTML5 Game: up to and including 1.3

Published 2026-09-02. Last modified 2026-09-03.