CVE-2026-103999

Description

The Ultra Addons for Contact Form 7 plugin for WordPress is vulnerable to Stored Cross-Site Scripting via File Upload in all versions up to, and including, 3.5.54 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The extension blocklist gatekeeper is bypassed by uploading text-type files (.txt, .csv, .vtt, .srt, .asc) whose contents begin with an HTML payload such as '<BODY onload=…>', as the check classifies these files as text/plain without inspecting their byte content.

References

https://www.wordfence.com/threat-intel/vulnerabilities/id/29b9d978-f8b0-48f9-a10e-7e61a4f4a828?source=cve

https://plugins.trac.wordpress.org/changeset/3738548/ultimate-addons-for-contact-form-7/trunk/addons/database/database.php

https://plugins.trac.wordpress.org/browser/ultimate-addons-for-contact-form-7/tags/3.5.52/inc/functions.php#L1703

https://plugins.trac.wordpress.org/browser/ultimate-addons-for-contact-form-7/tags/3.5.52/addons/database/database.php#L901

https://plugins.trac.wordpress.org/browser/ultimate-addons-for-contact-form-7/tags/3.5.52/addons/database/database.php#L895

https://plugins.trac.wordpress.org/browser/ultimate-addons-for-contact-form-7/tags/3.5.52/addons/database/database.php#L869

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-102660

https://downloads.wordpress.org/plugin/ultimate-addons-for-contact-form-7.zip

Details

Source: Mitre, NVD

Risk Information

CVSS v2

CVSS v3

EPSS