Pie Register Premium <= 3.8.4.0 — Unauthenticated Arbitrary File Upload via piereg_file_upload AJAX Handler
CVE-2026-84999Published · Updated Action summary
Affected: ≤3.8.4.0Update to 3.8.4.1 or newer
All remediation steps- Severity
- Critical9.8
- CVSS
- 9.8CVSS 3.1 · CNA (Wordfence)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HWhat does this vector mean?
AV:NAttack vector- Network
AC:LAttack complexity- Low
PR:NPrivileges required- None
UI:NUser interaction- None
S:UScope- Unchanged
C:HConfidentiality- High
I:HIntegrity- High
A:HAvailability- High
- Weakness
- CWE-434 Arbitrary File Upload
- Required access
- No account needed
- Exploit prediction (EPSS)
- 0.5% chance in 30 days42th percentile
- CISA KEV
- Not listed
On this page8
Am I affected?
Pie Register Premium pie-register-premium
- Affected≤ 3.8.4.0
- Patched in3.8.4.1
Update to 3.8.4.1 or newer.
You are affected if you run ≤ 3.8.4.0. Version 3.8.4.1 and later are not affected by this issue.
- Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under Pie Register Premium.
- No admin access? Run a passive check of your site. It reads public files only.
- No account is needed to exploit this. Treat any exposed site on an affected version as at risk.
What to do
- Update to version 3.8.4.1, or a newer patched version
- Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
- Watch Pie Register Premium to get an email when the next vulnerability is published.
Advisory
Source description from Wordfence Intelligence, credited to Chu Thao Mai.
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.
Exploits & references
Proof-of-concept & detection
No public proof-of-concept or detection template is known for this vulnerability.
Advisories & patches
- Advisorywordfence.com
Related CVEs
More in Pie Register Premium
All 6| Severity | Vulnerability | CVE | Published |
|---|---|---|---|
| Medium4.3 | Authenticated (Subscriber+) Limited File Deletion ≤3.8.3.2Update to 3.8.3.3 | CVE-2025-26940 | |
| Medium4.3 | Missing Authorization ≤3.8.3.2Update to 3.8.3.3 | CVE-2025-26948 | |
| Critical9.8 | Unauthenticated Arbitrary File Upload <3.8.3.3Update to 3.8.3.3 | CVE-2024-53822 | |
| Medium6.1 | Unauthenticated Cross-Site Scripting <3.8.3.3Update to 3.8.3.3 | CVE-2024-53821 | |
| Medium5.3 | Missing Authorization <3.8.3.3Update to 3.8.3.3 | CVE-2024-52391 |
- Medium4.3Authenticated (Subscriber+) Limited File Deletion
≤3.8.3.2Update to 3.8.3.3
- Medium4.3Missing Authorization
≤3.8.3.2Update to 3.8.3.3
- Critical9.8Unauthenticated Arbitrary File Upload
<3.8.3.3Update to 3.8.3.3
- Medium6.1Unauthenticated Cross-Site Scripting
<3.8.3.3Update to 3.8.3.3
- Medium5.3Missing Authorization
<3.8.3.3Update to 3.8.3.3
Same weakness (Arbitrary File Upload)
All Arbitrary File Upload| Severity | Vulnerability | CVE | Published |
|---|---|---|---|
| High7.2 | Unauthenticated Stored Cross-Site Scripting via Comment User-Agent Header | CVE-2026-120688 | |
| Critical9.8 | Unauthenticated Arbitrary File Upload via File Upload via Public Form Submission | CVE-2026-125055 | |
| Critical9.8 | Unauthenticated PHP Object Injection to Remote Code Execution via 'form' Parameter | CVE-2026-119077 | |
| Medium5.3 | Unauthenticated Sensitive Information Exposure in 'search' Parameter | CVE-2026-121518 |
- High7.2Unauthenticated Stored Cross-Site Scripting via Comment User-Agent Header
EZ SQL Reports Shortcode Widget and DB Backup
≤5.25.25Update to 5.26.45
- Critical9.8Unauthenticated Arbitrary File Upload via File Upload via Public Form Submission
Chatterbug Forms – Fast, Flexible WordPress Form Builder
≤1.0.2Update to 1.1
- Critical9.8Unauthenticated PHP Object Injection to Remote Code Execution via 'form' Parameter
ELEX WordPress HelpDesk & Customer Ticketing System
≤3.3.9Update to 3.4.0
- Medium5.3Unauthenticated Sensitive Information Exposure in 'search' Parameter
Customer Reviews for WooCommerce
≤5.127.0Update to 5.128.0
Timeline
CVE published
Severity critical, CVSS 9.8
Record last updated
Sources & licenses
Wordfence record- Vulnerability data
- Wordfence Intelligence. Copyright 2012-2026 Defiant Inc. Licensed under the CC BY-SA 4.0.
- CVE® identifiers
- Copyright 1999-2026 The MITRE Corporation. Used under the CVE Program. CVE® is a registered trademark of The MITRE Corporation.
- CVSS / CWE
- National Vulnerability Database (NVD), shown unmodified. This product uses the NVD API but is not endorsed or certified by the NVD.
- EPSS
- Exploit Prediction Scoring System by FIRST.org.
- VulnCrest content
- Summary, remediation guidance and page layout © VulnCrest. Not sourced from NVD.