MaxUpload <= 1.4.0 - Unauthenticated Arbitrary File Upload via 'resumableFilename' Parameter
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-434.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| sadathimel | MaxUpload – Big File Uploads – Increase Maximum File Upload Size | up to 1.4.0 | — | No fix listed | CNA |
- MaxUpload – Big File Uploads – Increase Maximum File Upload Size Vendorsadathimel Affected up to 1.4.0 Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-15965
- 2026-10-03 Alias added: GHSA-mq3w-pgpp-67hx
References
Other 6
- https://www.wordfence.com/threat-intel/vulnerabilities/id/70d90c0c-e3c6-4db9-b16d-1442e7e1dc3b?source=cve
- 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/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/maxupload-wp.php#L88
Sources
- CVE-2026-15965 · CVE Program
- CVE-2026-15965 · NVD
- FIRST EPSS
- GHSA-mq3w-pgpp-67hx · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences