---
id: CVE-2026-2354
title: >-
  The Swiss Toolkit For WP plugin for WordPress is vulnerable to arbitrary file
  upload due to a flawed file type validation bypass in the
  `upload_extension_files()` function in all versions up to, and including,
  1.4.6
summary: >-
  The Swiss Toolkit For WP plugin for WordPress is vulnerable to arbitrary file
  upload due to a flawed file type validation bypass in the
  `upload_extension_files()` function in all versions up to, and including,
  1.4.6. The `upload_extensio…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-434
published: '2026-07-11'
updated: '2026-07-11'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-2354'
references:
  - url: >-
      https://plugins.trac.wordpress.org/browser/swiss-toolkit-for-wp/tags/1.4.2/includes/plugins/class-boomdevs-swiss-toolkit-extension-supports.php#L49
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/swiss-toolkit-for-wp/tags/1.4.2/includes/plugins/class-boomdevs-swiss-toolkit-extension-supports.php#L95
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/swiss-toolkit-for-wp/trunk/includes/plugins/class-boomdevs-swiss-toolkit-extension-supports.php#L49
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/swiss-toolkit-for-wp/trunk/includes/plugins/class-boomdevs-swiss-toolkit-extension-supports.php#L95
    label: security@wordfence.com
  - url: >-
      https://www.wordfence.com/threat-intel/vulnerabilities/id/06bccd2e-6891-433a-9f5b-3ec0c30afef4?source=cve
    label: security@wordfence.com
tags:
  - nvd
epss: 0.00999
epssPercentile: 0.6117
ingestedAt: '2026-07-11T23:16:20.461Z'
---

## Overview

The Swiss Toolkit For WP plugin for WordPress is vulnerable to arbitrary file upload due to a flawed file type validation bypass in the `upload_extension_files()` function in all versions up to, and including, 1.4.6. The `upload_extension_files()` function hooks into WordPress's `wp_check_filetype_and_ext` filter and uses `strpos()` to check if a filename contains a configured extension string, rather than verifying the actual file extension. This makes it possible for authenticated attackers, with Author-level access and above, to upload arbitrary files (including PHP) on the affected site's server which may make remote code execution possible, granted the "Enhanced Multi-Format Image Support" feature is enabled with at least one extension (e.g., avif) in the allowed formats.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.