CVE-2026-82901

Ultra Addons for Contact Form 7 <= 3.5.50 - Unauthenticated Arbitrary File Upload via Signature Form Field

2026-09-26 06:02
Supakiad S. (m3ez)

Strategic Overview

Status
Patched in 3.5.51
Affected Plugin
Ultra Addons for Contact Form 7
Affected Version
<= 3.5.50
CVSS
9.8Critical
Weakness type
CWE-434 · Unrestricted Upload of File with Dangerous Type
CVE
CVE-2026-82901
View all Ultra Addons for Contact Form 7 vulnerabilities

At a glance

CVE-2026-82901 is a critical-severity Unrestricted Upload of File with Dangerous Type vulnerability in the Ultra Addons for Contact Form 7 WordPress plugin, affecting versions <= 3.5.50. It carries a CVSS score of 9.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. The issue is fixed in version 3.5.51; sites on affected versions should update now. Disclosed September 2026, reported by Supakiad S. (m3ez).

Vulnerability Overview

The Ultra Addons for Contact Form 7 plugin for WordPress is vulnerable to Arbitrary File Upload due to insufficient file type validation in the 'uacf7_wpcf7_mail_components' function in all versions up to, and including, 3.5.50. 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: This is only exploitable when the plugin's PDF Generator module is enabled, which is disabled by default.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-434: Unrestricted Upload of File with Dangerous Type

Ultra Addons for Contact Form 7 <= 3.5.50 carries this weakness at uacf7_wpcf7_mail_components, and reaching it takes no account at all. An unrestricted file upload lets a caller store a file whose type or destination the application does not properly constrain.

If an uploaded file lands anywhere the server will execute, the flaw becomes remote code execution and the site should be treated as fully compromised. For Ultra Addons for Contact Form 7 the fix is 3.5.51: builds <= 3.5.50 are affected, anything from 3.5.51 onward is not.

Remediation

Update to version 3.5.51, or a newer patched version

How does WordSec protect against this?

Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. Classes like this one can leave something behind, so the staged malware scanner is the second half: it looks for dropped files and modified code rather than for the request that created them. None of that substitutes for the fix: Ultra Addons for Contact Form 7 3.5.51 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Scanner
  • Login Security

External References

https://www.cve.org/CVERecord?id=CVE-2026-82901https://www.wordfence.com/threat-intel/vulnerabilities/id/872e1a05-aacc-44fa-93c1-8c3f7b2fb46dhttps://nvd.nist.gov/vuln/detail/CVE-2026-82901

Related records

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