PatchTheCVECVE-2026-84999: The Pie Register Premium plugin for WordPress is vulnerable to Unrestricted File Type Upload in all versions u
CVE-2026-84999 is a critical-severity flaw (CVSS 9.8) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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 hand
Why this priority
- Critical severity
- Remotely exploitable, no login, no user action
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 9.8 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | n/a |
| CISA exploited list | No |
| Weakness | CWE-434 |
| Published | 2026-10-28 |
| Last modified | 2026-10-28 |
Last updated 2026-10-28 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Advisories and coverage
Research and news
- Vulners Bulletins: CVE-2026-84999 2026-10-28
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-84999?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-84999 being exploited?
CVE-2026-84999 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-84999 affect?
CVE-2026-84999 affects affected software. Severity is critical (CVSS 9.8). 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
How urgent is CVE-2026-84999?
Priority 39/100. Critical severity; Remotely exploitable, no login, no user action