Vulnerability Description
The Pie Register Premium plugin for WordPress is vulnerable to Unrestricted File Type Upload in all versions up to, and including, 3.8.4.0 via the piereg_file_upload function. This is due to the plugin performing file type validation via wp_check_filetype and wp_check_filetype_and_ext but never checking whether those validation calls produced errors before move_uploaded_file() is called, combined with no nonce or capability check on the AJAX handler. This makes it possible for unauthenticated attackers to upload files of dangerous types (e.g. PHP scripts) that may be executable, which makes remote code execution possible. The server returns the generated destination filename in the response, giving the attacker the exact path needed to trigger the uploaded file.
CVSS Score
CRITICAL
Related Weaknesses (CWE)
References
- https://pieregister.com/
- https://www.wordfence.com/threat-intel/vulnerabilities/id/8385dd30-28e5-4572-850
FAQ
What is CVE-2026-84999?
CVE-2026-84999 is a vulnerability with a CVSS score of 9.8 (CRITICAL). The Pie Register Premium plugin for WordPress is vulnerable to Unrestricted File Type Upload in all versions up to, and including, 3.8.4.0 via the piereg_file_upload function. This is due to the plugi...
How severe is CVE-2026-84999?
CVE-2026-84999 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-84999?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.