Vulnerabilities / Nexter Extension – Site Enhancements Toolkit / WPSEC-2026-0981
Nexter Extension – Site Enhancements Toolkit <= 4.7.6 - Authenticated (Author+) Arbitrary File Upload via Custom Font Upload
High 7.5
CWE-434Fixed in 4.7.7
- ID
- WPSEC-2026-0981
- Plugin
- Nexter Extension – Security, Performance, Code Snippets & Site Toolkit (nexter-extension)
- Affected
- all versions before 4.7.7
- Remediation
- Update to 4.7.7 or later.
- CVSS 3.1
- CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness
- CWE-434
- Usage
- Plugin Low · Affected versions None seen among sites WPSec scans, 2026-10-15
- Attack surface
- Nexter Extension – Site Enhancements Toolkit on WPSec AttackSurface
- Fix released
- Published
Description
The Nexter Extension plugin for WordPress is vulnerable to arbitrary file uploads via the Custom Upload Font feature in all versions up to, and including, 4.7.6. This is due to insufficient file type validation in the nxt_check_file_ext function, which used a substring match so that a filename such as 'x.ttf.php' was treated as a font. This makes it possible for authenticated attackers with Author-level access and above, who can upload media, to upload arbitrary files such as PHP scripts to the server, which may lead to remote code execution. The Custom Upload Font extension must be enabled.
References
- https://wpsec.com/vuln/WPSEC-2026-0981/
- https://plugins.svn.wordpress.org/nexter-extension/tags/4.7.7/
- https://wordpress.org/plugins/nexter-extension/
Published by WPSec. Provided as is, without warranty. Corrections: contact us.
This advisory as JSON or Markdown · All advisories: JSON, RSS