9.8

CVE-2026-84999: Pie Register Premium <= 3.8.4.0 - Unauthenticated Arbitrary File Upload via piereg_file_upload AJAX Handler

Received
Published 28-10-2026Last modified 28-10-2026

Vulnerability summary

CVE-2026-84999 is a critical (CVSS 9.8) vulnerability in pie register pie register premium.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS scoreNot scoredRisk metrics not yet published.
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 28-10-2026
    PublishedVulnerability first disclosed.

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 metrics

2 scores · 2 sources · 1 version

EPSS trend

No EPSS score has been published for this record yet.

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Pie register1 product

1 vendor · 1 product

References

2 links