CVE-2026-18983
Received Received - Intake

Stored XSS in One User Avatar WordPress Plugin

Publication date: 2026-08-28

Last updated on: 2026-08-28

Assigner: Wordfence

Description
The One User Avatar | User Profile Picture plugin for WordPress is vulnerable to Stored Cross-Site Scripting in all versions up to, and including, 2.5.4 via the wpua_action_process_option_update function. This is due to insufficient file type validation in wp_handle_upload() called without a MIME allow-list, with post-write validation relying on the attacker-controlled client-supplied Content-Type header rather than a server-derived type, and no cleanup of files that fail the check. This makes it possible for authenticated attackers, with subscriber-level access and above, to upload files that may be executable, which makes remote code execution possible. in order to exploit this vulnerability an admin has to give subscribers permission to upload avatars. While PHP files and svg files are rejected, dxfp files are accepted.

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Meta Information

Published
2026-08-28
Last Modified
2026-08-28
Generated
2026-08-28
AI Q&A
2026-08-28
EPSS Evaluated
N/A
NVD
CVE-2026-18983
EUVD
EUVD-2026-67408

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
wp_user_avatar wp_user_avatar to 2.5.4 (inc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-434 The product allows the upload or transfer of dangerous file types that are automatically processed within its environment.

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Executive Summary

The One User Avatar plugin for WordPress has a stored Cross-Site Scripting (XSS) vulnerability in versions up to 2.5.4. It allows authenticated attackers with subscriber-level access or higher to upload executable files by bypassing file type validation. The plugin fails to properly validate file types during upload, relying on attacker-controlled headers instead of server-derived types. This can lead to remote code execution if an admin grants avatar upload permissions to subscribers.

Impact Analysis

If you use the One User Avatar plugin in WordPress, attackers could exploit this to upload malicious files to your site. This could allow them to execute arbitrary code on your server, potentially taking control of your website. The attack requires only subscriber-level access, which is a low-privilege role, making it easier for attackers to exploit.

Compliance Impact

This vulnerability could lead to unauthorized code execution on your server, which may result in data breaches. For GDPR, this could mean non-compliance due to unauthorized access to personal data. For HIPAA, it could risk exposure of protected health information. Both regulations require safeguards against unauthorized access, which this vulnerability undermines.

Mitigation Strategies

Update the One User Avatar | User Profile Picture plugin to the latest version beyond 2.5.4 to patch the vulnerability. Disable avatar uploads for subscribers if not required. Implement strict file type validation and server-derived MIME type checks for uploaded files.

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