CVE-2026-4883
Published: 19 May 2026
Summary
CVE-2026-4883 is a critical-severity Unrestricted Upload of File with Dangerous Type (CWE-434) vulnerability in Piotnetforms (inferred from references). Its CVSS base score is 9.8 (Critical).
Operationally, ranked at the 35.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
Threat & Defense Details
Likely Mitigating ControlsAI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Requiring identifiable owners for portable devices reduces the attack surface for unrestricted uploads of dangerous file types via anonymous media.
Dangerous file uploads can be detonated in the chamber to determine malice before any production write or execution occurs.
Prevents unrestricted writing of arbitrary or malicious firmware by keeping hardware write-protect enabled except under tightly controlled manual procedures.
Scans files from external sources on download/open/execute, blocking unrestricted uploads of dangerous file types.
NVD 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…
more
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.
Deeper analysisAI
Automated synthesis unavailable for this CVE.
Details
- CWE(s)