CVE-2026-15965 MaxUpload <= 1.4.0 - Unauthenticated Arbitrary File Upload via 'resumableFilename' Parameter
Unauthenticated attackers can upload executable files via the resumableFilename parameter, leading to remote code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-15965?
CVE-2026-15965 is a high-severity vulnerability in sadathimel MaxUpload – Big File Uploads – Increase Maximum File Upload Size, published on 15 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-434
Which versions are affected by CVE-2026-15965?
How do I fix CVE-2026-15965?
No fix has been published for CVE-2026-15965 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-15965 being exploited?
There is no known exploitation of CVE-2026-15965 in the wild and no public exploit code.
Sources
Also known as GHSA-mq3w-pgpp-67hx.