CVE-2026-49055: Contact Form 7 File Upload XSS Flaw

CVE-2026-49055 Overview

CVE-2026-49055 is an unauthenticated Cross-Site Scripting (XSS) vulnerability in the WordPress plugin Drag and Drop Multiple File Upload – Contact Form 7. The flaw affects all plugin versions up to and including 1.3.9.7. Attackers can inject malicious script content that executes in the context of a victim's browser after user interaction. The vulnerability is categorized under [CWE-79] and requires no authentication to exploit. Patchstack has published an advisory documenting the issue.

Critical Impact
Unauthenticated attackers can execute arbitrary JavaScript in a victim's browser session, enabling session theft, credential harvesting, and unauthorized actions on the affected WordPress site.

Affected Products

Drag and Drop Multiple File Upload – Contact Form 7 WordPress plugin
All plugin versions up to and including 1.3.9.7
WordPress sites with the vulnerable plugin enabled

Discovery Timeline

2026-06-15 - CVE-2026-49055 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2026-49055

Vulnerability Analysis

The vulnerability is a reflected or stored Cross-Site Scripting (XSS) flaw classified under [CWE-79]. The plugin fails to properly sanitize or encode user-supplied input before rendering it in HTML output. An attacker can craft a request containing malicious JavaScript payloads that the plugin echoes back without adequate escaping.

The scope of the issue is changed, meaning script execution can affect resources beyond the vulnerable component. Successful exploitation requires user interaction, typically through a crafted link or a visit to an attacker-controlled page. The impact spans confidentiality, integrity, and availability at limited levels.

Root Cause

The root cause is improper neutralization of input during web page generation. The plugin accepts user-controlled parameters tied to file upload handling and contact form processing but does not apply output encoding before reflecting that input into the DOM. WordPress sanitization helpers such as esc_html(), esc_attr(), or wp_kses() were either not applied or were applied incorrectly to the affected sinks.

Attack Vector

The attack vector is network-based and unauthenticated. An attacker constructs a URL or form submission containing a JavaScript payload targeting the vulnerable plugin endpoint. The victim must interact with the malicious link or page for the payload to execute. Once triggered, the script runs in the victim's browser under the origin of the affected WordPress site, enabling cookie theft, session hijacking, defacement, or pivoting to administrative actions if the victim holds elevated privileges.

No verified public exploit code is available at this time. Technical details are documented in the Patchstack Vulnerability Report.

Detection Methods for CVE-2026-49055

Indicators of Compromise

Inbound HTTP requests to Contact Form 7 file upload endpoints containing <script>, javascript:, onerror=, or onload= patterns in query strings or POST bodies.
WordPress access logs showing unusual referrers leading to plugin endpoints followed by outbound requests to unfamiliar domains.
Unexpected JavaScript content reflected in cached HTML responses from the affected plugin pages.

Detection Strategies

Inspect web server and WordPress logs for suspicious parameter values targeting the drag-and-drop-multiple-file-upload-contact-form-7 plugin paths.
Deploy Web Application Firewall (WAF) rules matching common XSS payload signatures against plugin endpoints.
Monitor browser-side Content Security Policy (CSP) violation reports for unauthorized inline script execution.

Monitoring Recommendations

Enable verbose logging on the WordPress instance and forward logs to a centralized analytics platform for correlation.
Alert on outbound connections from end-user browsers to known credential-exfiltration or attacker-controlled infrastructure.
Track plugin version inventory across WordPress estates to identify hosts running 1.3.9.7 or earlier.

How to Mitigate CVE-2026-49055

Immediate Actions Required

Update the Drag and Drop Multiple File Upload – Contact Form 7 plugin to a version newer than 1.3.9.7 as soon as a fixed release is available from the vendor.
Audit all WordPress installations to identify deployments running the affected plugin version.
Review WordPress administrator and editor account activity for signs of session compromise.

Patch Information

Consult the Patchstack Vulnerability Report for the latest remediation status and fixed version information. Apply the patched plugin release through the WordPress admin dashboard or via wp-cli once the vendor publishes it.

Workarounds

Disable the affected plugin until a patched version is installed if business operations allow.
Deploy a strict Content Security Policy (CSP) that blocks inline scripts and untrusted external script sources.
Configure WAF rules to block requests containing XSS payloads targeting the plugin's file upload endpoints.
Restrict access to contact form pages using IP allowlists or authentication where feasible.

bash

# Configuration example: identify affected plugin version via wp-cli
wp plugin list --name=drag-and-drop-multiple-file-upload-contact-form-7 --fields=name,status,version

# Disable the plugin until patched
wp plugin deactivate drag-and-drop-multiple-file-upload-contact-form-7

# After vendor patch is available, update to the fixed release
wp plugin update drag-and-drop-multiple-file-upload-contact-form-7