Quick answers
- Is CVE-2026-84999 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-84999 being exploited in the wild.
- How severe is CVE-2026-84999?
- Critical severity, with a CVSS score of 9.8, published 28 October 2026.
- Which products and versions are affected?
- Pie Register Premium up to and including 3.8.4.0.
- Is there a fix for CVE-2026-84999?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-84999 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-84999?
- Check whether you run Pie Register Premium at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The piereg_file_upload AJAX handler validates file types using wp_check_filetype and wp_check_filetype_and_ext but does not check for validation errors before calling move_uploaded_file(), and lacks nonce or capability checks. This allows unauthenticated attackers to upload dangerous file types (including executable PHP scripts) that can be accessed via the returned file path to achieve remote code execution.
Affected products
- Pie Register Pie Register Premium up to and including 3.8.4.0
Timeline
- 2026-10-28: disclosed