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CVE-2026-4883

Piotnet Forms <= 2.1.40 - Unauthenticated Arbitrary File Upload via Form File Upload

Critical9.8EPSS 3.1%
Published
Updated
Reserved
Assigned by
Wordfence

Description

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.

Scores

CVSS scores of CVE-2026-4883, by who scored it
Scored byCVSSScoreVector
WordfenceCNA (assigner)3.1Critical9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVDNVD · Deferred3.1Critical9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (exploitation in 30 days)
3.1% · top 12% of all CVEs (6 Nov 2026)
CISA SSVC
Exploitation: none · Automatable: yes · Technical impact: total
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The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.

Weakness

Affected products

References (2)

Sources

The same CVE in the primary databases and aggregators, to check against.

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Record last updated .