What’s Vulnerable › Vulnerabilities
CVE-2026-15965: MaxUpload <= 1.4.0 - Unauthenticated Arbitrary File Upload via 'resumableFilename' Parameter
- Severity: high (CVSS 8.8 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 1.0% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-08-15 · updated 2026-08-20
- Weakness: CWE-434
Description
The MaxUpload – Big File Uploads – Increase Maximum File Upload Size plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 1.4.0 via the handle_upload function. This is due to a filename-validation mismatch in the handle_upload function where extension and MIME checks are applied to the uploaded chunk's filename but not to the final assembled filename derived from the resumableFilename parameter. This makes it possible for unauthenticated attackers to upload files that may be executable, which makes remote code execution possible.
Affected products
References
- https://plugins.trac.wordpress.org/browser/maxupload-upload-larger-files-easily/tags/1.4.0/includes/uploader.php#L121
- https://plugins.trac.wordpress.org/browser/maxupload-upload-larger-files-easily/tags/1.4.0/includes/uploader.php#L174
- https://plugins.trac.wordpress.org/browser/maxupload-upload-larger-files-easily/tags/1.4.0/includes/uploader.php#L19
- https://plugins.trac.wordpress.org/browser/maxupload-upload-larger-files-easily/tags/1.4.0/includes/uploader.php#L201
- https://plugins.trac.wordpress.org/browser/maxupload-upload-larger-files-easily/tags/1.4.0/maxupload-wp.php#L88
- https://www.wordfence.com/threat-intel/vulnerabilities/id/70d90c0c-e3c6-4db9-b16d-1442e7e1dc3b?source=cve
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