CVE-2026-34735: Hytalemodding Wiki

High severity, CVSS 8.7. EPSS: 0.5% chance of exploitation in the next 30 days.

The Hytale Modding Wiki is a free service for Hytale mods to host their documentation & wikis. In version 1.2.0 and prior, the quickUpload() endpoint validates uploaded files by checking their MIME type (via PHP's finfo, which inspects file contents) but constructs the stored filename using the client-supplied file extension from getClientOriginalExtension(). These two checks are independent: an attacker can upload a file whose content passes the MIME allowlist while using a .php extension. The file is stored on the public disk and is directly accessible via URL, allowing server-side code execution. At time of publication no known patches exist.

Affected products

• Hytalemodding Wiki: up to and including 1.2.0

Published 2026-04-02. Last modified 2026-07-24.