The Piotnet Forms plugin for WordPress is vulnerable to arbitrary file upload due to missing file type validation in the 'piotnetforms_ajax_form_builder' function in all versions up to, and including, 2.1.40. The plugin uses an incomplete extension blacklist that only blocks php, phpt, php5, php7, and exe extensions, while allowing dangerous extensions such as .phar or .phtml to be uploaded. This makes it possible for unauthenticated attackers to upload arbitrary files on the affected site's server which may make remote code execution possible. Note: The exploit can only be exploited if a file field is added to the form.
CVE-2026-4883 is a critical severity with CVSS 9.8 Remote Code Execution issue affecting the Plugin Piotnet Forms. It affects Versions up to 2.1.40 and is listed without a confirmed patched release.
Use the related hub and response guides to connect this CVE-2026-4883 report with patch validation, scanner checks, and site hardening work.
Open the grouped hub for related CVEs, affected ranges, severity mix, and patch coverage.
Check access, XML-RPC exposure, backup readiness, and monitoring after patching.
Use containment, evidence capture, remediation, and validation steps when exploit risk is high.
CVE-2026-4883 is tracked for the Plugin Piotnet Forms as critical severity with CVSS 9.8. The affected range is Versions up to 2.1.40. No fixed release is listed in this feed entry, so operators should monitor the vendor and reference links before accepting the risk.
Search engines and operators need more than a title. This page exposes the identifier, affected range, patch evidence, and source coverage that make the vulnerability actionable.
This report has a CVE identifier, which makes it suitable for focused search and vulnerability triage workflows.
Affected version data gives operators a concrete comparison point against installed WordPress software.
No patched version is listed, so the record is useful mainly for monitoring and risk acceptance decisions.
External references are available for source validation, advisory review, and incident notes.
Use these checks when converting this record into a patch ticket, incident note, or risk acceptance decision.
Inventory the installed Plugin package and compare its version with Versions up to 2.1.40.
Monitor vendor advisories because this Remote Code Execution issue has no fixed release listed here.
Review references and CVSS vector details for exploitability, authentication requirements, and exposure path.
After patching, re-run vulnerability monitoring and keep the related plugin or theme hub under review for follow-up CVEs.
| Software Type | Plugin |
|---|---|
| Software Slug |
piotnetforms-pro
View on wordpress.org
|
| CVE | CVE-2026-4883 |
| Patched Versions |
No patched versions published.
|
| Affected Versions |
Versions up to 2.1.40
|
This record contains material that is subject to copyright
License: Defiant hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute this software vulnerability information. Any copy of the software vulnerability information you make for such purposes is authorized provided that you include a hyperlink to this vulnerability record and reproduce Defiant's copyright designation and this license in any such copy. Read more
License: CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE®). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy. Read more
