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

> Authenticated attackers can upload arbitrary files, including PHP, leading to remote code execution if the Enhanced Multi-Format Image Support feature is enabled.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 Jul 2026
- **Updated:** 13 Jul 2026
- **Also known as:** GHSA-xq2v-8qf4-3rg6

## What is CVE-2026-2354?

CVE-2026-2354 is a high-severity vulnerability in wpmessiah Swiss Toolkit For WP, published on 11 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official 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.

Weakness: CWE-434 (Unrestricted Upload of File with Dangerous Type)

## Which versions are affected by CVE-2026-2354?


## How do I fix CVE-2026-2354?

No fix has been published for CVE-2026-2354 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-2354 being exploited?

There is no known exploitation of CVE-2026-2354 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-2354 and fix it if it is affected.

What it is: CVE-2026-2354 is a high-severity vulnerability in wpmessiah Swiss Toolkit For WP, published on 11 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-2354 in the wild and no public exploit code.

Affected product: wpmessiah Swiss Toolkit For WP. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-2354/ (Markdown: https://insights.sbomify.com/CVE-2026-2354/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-2354
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-2354
- OSV: https://osv.dev/vulnerability/CVE-2026-2354

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-2354/
Summaries are generated and may contain mistakes; the official description above is the record.