CVE-2026-1306
📋 TL;DR
The midi-Synth WordPress plugin allows unauthenticated attackers to upload arbitrary files due to missing validation in the 'export' AJAX action. This can lead to remote code execution if attackers obtain a valid nonce, which is exposed in frontend JavaScript. All WordPress sites using midi-Synth version 1.1.0 or earlier are affected.
💻 Affected Systems
- WordPress midi-Synth plugin
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete server compromise, data theft, malware deployment, and persistent backdoor installation.
Likely Case
Arbitrary file upload leading to webshell deployment, defacement, or limited code execution within WordPress context.
If Mitigated
File upload attempts blocked by web application firewall or server-side restrictions, with only failed attempts logged.
🎯 Exploit Status
Nonce is exposed in frontend JavaScript, making exploitation trivial for unauthenticated attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.1.1 or later
Vendor Advisory: https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&new=3078287%40midi-synth%2Ftrunk&old=3078286%40midi-synth%2Ftrunk
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find midi-Synth plugin. 4. Click 'Update Now' if update available. 5. If no update available, deactivate and delete plugin immediately.
🔧 Temporary Workarounds
Disable midi-Synth plugin
allDeactivate and remove the vulnerable plugin from WordPress
wp plugin deactivate midi-synth
wp plugin delete midi-synth
Web Application Firewall rule
linuxBlock requests to midi-synth AJAX endpoints
# Add to .htaccess for Apache:
RewriteRule ^wp-content/plugins/midi-synth/.* - [F,L]
# Add to nginx config:
location ~* /wp-content/plugins/midi-synth/ { deny all; }
🧯 If You Can't Patch
- Immediately deactivate and remove the midi-Synth plugin from all WordPress installations
- Implement strict file upload restrictions at web server level to block PHP and executable file uploads
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin panel → Plugins → Installed Plugins for midi-Synth version 1.1.0 or earlierCheck Version:
wp plugin get midi-synth --field=versionVerify Fix Applied:
Verify midi-Synth plugin is either updated to version 1.1.1+ or completely removed from plugins directory📡 Detection & Monitoring
Log Indicators:
- POST requests to /wp-admin/admin-ajax.php with action=midi_synth_export
- File uploads to wp-content/uploads/midi-synth/ directory with suspicious extensions
- Unauthenticated requests to midi-synth AJAX endpoints
Network Indicators:
- HTTP POST requests containing 'midi_synth_export' in parameters
- Uploads of files with double extensions like .php.jpg
SIEM Query:
source="web_logs" AND (uri_path="/wp-admin/admin-ajax.php" AND post_data CONTAINS "midi_synth_export")🔗 References
- https://plugins.trac.wordpress.org/browser/midi-synth/tags/1.1.0/midiSynth.php#L110
- https://plugins.trac.wordpress.org/browser/midi-synth/tags/1.1.0/midiSynth.php#L121
- https://plugins.trac.wordpress.org/browser/midi-synth/tags/1.1.0/midiSynthConvert.php#L421
- https://plugins.trac.wordpress.org/browser/midi-synth/tags/1.1.0/midiSynthConvert.php#L492
- https://www.wordfence.com/threat-intel/vulnerabilities/id/d5b695d7-c690-4748-b218-5699d1aa63bf?source=cve
