Piotnet Forms Plugin up to 2.1.40 on WordPress piotnetforms_ajax_form_builder File unrestricted upload

Summaryinfo

A vulnerability, which was classified as critical, was found in Piotnet Forms Plugin up to 2.1.40 on WordPress. Affected by this issue is the function piotnetforms_ajax_form_builder. Executing a manipulation of the argument File can lead to unrestricted upload. This vulnerability appears as CVE-2026-4883. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability classified as critical was found in Piotnet Forms Plugin up to 2.1.40 on WordPress. This vulnerability affects the function piotnetforms_ajax_form_builder. The manipulation of the argument file with an unknown input leads to a unrestricted upload vulnerability. The CWE definition for the vulnerability is CWE-434. The product allows the attacker to upload or transfer files of dangerous types that can be automatically processed within the product's environment. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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.

The weakness was presented by Jude Nwadinobi. The advisory is available at wordfence.com. This vulnerability was named CVE-2026-4883 since 03/26/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 05/19/2026). This vulnerability is assigned to T1608.002 by the MITRE ATT&CK project.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• WordPress Plugin

Vendor

• Piotnet

Name

• Forms Plugin

Version

• 2.1.0
• 2.1.1
• 2.1.2
• 2.1.3
• 2.1.4
• 2.1.5
• 2.1.6
• 2.1.7
• 2.1.8
• 2.1.9
• 2.1.10
• 2.1.11
• 2.1.12
• 2.1.13
• 2.1.14
• 2.1.15
• 2.1.16
• 2.1.17
• 2.1.18
• 2.1.19
• 2.1.20
• 2.1.21
• 2.1.22
• 2.1.23
• 2.1.24
• 2.1.25
• 2.1.26
• 2.1.27
• 2.1.28
• 2.1.29
• 2.1.30
• 2.1.31
• 2.1.32
• 2.1.33
• 2.1.34
• 2.1.35
• 2.1.36
• 2.1.37
• 2.1.38
• 2.1.39
• 2.1.40

CPE 2.3info

• 🔒
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CPE 2.2info

• 🔒
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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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