Arbitrary file upload in Ultra Addons For Contact Form 7

CVE-2026-84750

The Ultra Addons for Contact Form 7 WordPress plugin before 3.5.51 does not validate the type or extension of files uploaded through one of its form fields, and stores them at a predictable public path with the attacker-chosen extension intact, allowing unauthenticated users to upload arbitrary files. The PHP handler shipped by default with the Debian and Ubuntu Apache packages maps .phar to PHP alongside .php and .phtml, so on that stack the uploaded file is executed and the issue leads to Remote Code Execution and full site takeover. Where the host routes only .php to the PHP handler, the same file is instead served from the site's own origin with its script intact, leading to Stored Cross-Site Scripting.

Vulnerability class: Unrestricted File Upload

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (38.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 39th percentile — 38.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-84750: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

  • Ultra Addons For Contact Form 7

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-84750?
CVE-2026-84750 is a medium-severity vulnerability in Ultra Addons For Contact Form 7, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 6.5/10. Published 2026-09-19.
How severe is CVE-2026-84750?
Medium severity. CVSS v3 base score is 6.5 out of 10.