CVE-2026-15965
MaxUpload <= 1.4.0 - Unauthenticated Arbitrary File Upload via 'resumableFilename' Parameter
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
8.8
MaxUpload <= 1.4.0 - Unauthenticated Arbitrary File Upload via 'resumableFilename' Parameter
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.
- Record
CVE-2026-15965- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-434
- Updated
- 2026-11-02
EUVDEUVD-2026-58837
8.8
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.
- Record
EUVD-2026-58837- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-mq3w-pgpp-67hx
8.8
The MaxUpload – Big File Uploads – Increase Maximum File Upload Size plugin for WordPress is...
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.
- Record
GHSA-mq3w-pgpp-67hx- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-434
- Updated
- 2026-11-02
NVD
8.8
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.
- Record
CVE-2026-15965- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-434
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-15965 is a high vulnerability (CVSS 8.8) in Sadathimel Maxupload – Big File Uploads – Increase Maximum File Upload Size, published August 15, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.03%, the 63rd percentile. No source names a fixed version.
References
wordfence.com/threat-intel/vulnerabilities/id/70d90c0c-e3c6-4db9-b16d-1442e7e1dc3b?source=cve
plugins.trac.wordpress.org/browser/maxupload-upload-larger-files-easily/tags/1.4.0/includes/uploader.php
plugins.trac.wordpress.org/browser/maxupload-upload-larger-files-easily/tags/1.4.0/maxupload-wp.php
nvd.nist.gov/vuln/detail/CVE-2026-15965
github.com/advisories/GHSA-mq3w-pgpp-67hx