Arbitrary File Upload Vulnerability in Piotnet Forms Plugin for WordPress
CVE-2026-4883

9.8CRITICAL

Key Information:

Vendor

WordPress
Status
Piotnet Forms
Vendor
CVE Published:
19 May 2026

What is CVE-2026-4883?

The Piotnet Forms plugin for WordPress is susceptible to an arbitrary file upload vulnerability due to inadequate file type validation in the 'piotnetforms_ajax_form_builder' function. The plugin's extension blacklist is insufficient, as it only blocks certain extensions (php, phpt, php5, php7, exe) but permits the upload of potentially harmful file types like .phar and .phtml. This flaw enables unauthenticated attackers to leverage file fields within forms to upload arbitrary files on the server, raising concerns for potential remote code execution.

Affected Version(s)

Piotnet Forms 0 <= 2.1.40

References

https://www.wordfence.com/threat-intel/vulnerabilities/id...
https://piotnetforms.com

CVSS V3.1

Score:
9.8
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Jude Nwadinobi
.