# CVE-2026-1306: midi-Synth <= 1.1.0 - Unauthenticated Arbitrary File Upload via 'export' AJAX Action

> Unauthenticated attackers can upload arbitrary files via the export AJAX action, potentially leading to remote code execution.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Feb 2026
- **Updated:** 8 Apr 2026
- **Also known as:** GHSA-6m5f-57jg-w742

## What is CVE-2026-1306?

CVE-2026-1306 is a critical vulnerability in adminkov midi-Synth, published on 14 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The midi-Synth plugin for WordPress is vulnerable to arbitrary file uploads due to missing file type and file extension validation in the 'export' AJAX action in all versions up to, and including, 1.1.0. This makes it possible for unauthenticated attackers to upload arbitrary files on the affected site's server which may make remote code execution possible granted the attacker can obtain a valid nonce. The nonce is exposed in frontend JavaScript making it trivially accessible to unauthenticated attackers.

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

## Which versions are affected by CVE-2026-1306?


## How do I fix CVE-2026-1306?

No fix has been published for CVE-2026-1306 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-1306 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-1306 exists.

Public exploit code:

- PoC list runner for CVE-2026-1306 (WordPress midi-Synth ≤1.1.0): fetches exposed midiSynth_nonce, POSTs export AJAX to drop files under sound/. Authorized security testing only. (github_poc): https://github.com/murrez/CVE-2026-1306
- The midi-Synth plugin for WordPress is vulnerable to arbitrary file uploads due to missing file type and file extension validation in the 'export' AJAX action in all versions up to, and including, 1.1.0. This makes it possible for unauthenticated attackers to upload arbitrary files on the affected site's server which may make remote code execution  (github_poc): https://github.com/SecureNet-Dynamics/CVE-2026-1306
- WordPress midi-Synth <= 1.1.0 - Unauthenticated Arbitrary File Upload (nuclei): http/cves/2026/CVE-2026-1306.yaml

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-1306 and fix it if it is affected.

What it is: CVE-2026-1306 is a critical vulnerability in adminkov midi-Synth, published on 14 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-1306 exists.

Affected product: adminkov midi-Synth. 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-2026-1306/ (Markdown: https://insights.sbomify.com/CVE-2026-1306/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-1306
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-1306
- OSV: https://osv.dev/vulnerability/CVE-2026-1306

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-1306/
Summaries are generated and may contain mistakes; the official description above is the record.