Arbitrary file upload in Embed Html5 Game

CVE-2026-4357

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.

Vulnerability class: Unrestricted File Upload

Published · last modified .

CVSS v3 metric

CVSS v3 base score 10.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.005 (44.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 44.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-4357: held from 0.003 to 0.005.

EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002

Affected products

  • Embed Html5 Game

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-4357?
CVE-2026-4357 is a critical-severity vulnerability in Embed Html5 Game, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 10.0/10. Published 2026-09-02.
How severe is CVE-2026-4357?
Critical severity. CVSS v3 base score is 10.0 out of 10.