CVE-2026-0946: Drupal AT Internet SmartTag XSS Flaw

CVE-2026-0946 Overview

CVE-2026-0946 is a Cross-Site Scripting (XSS) vulnerability affecting the Drupal AT Internet SmartTag module. The vulnerability stems from improper neutralization of input during web page generation, allowing attackers to inject malicious scripts into web pages viewed by other users. This vulnerability affects AT Internet SmartTag versions from 0.0.0 before 1.0.1.

Critical Impact

Attackers can exploit this XSS vulnerability to execute arbitrary JavaScript code in the context of a victim's browser session, potentially leading to session hijacking, credential theft, or defacement of Drupal sites using the affected module.

Affected Products

• Drupal AT Internet SmartTag versions 0.0.0 to 1.0.0

Discovery Timeline

• February 4, 2026 - CVE-2026-0946 published to NVD
• February 5, 2026 - Last updated in NVD database

Technical Details for CVE-2026-0946

Vulnerability Analysis

This vulnerability is classified as CWE-79 (Improper Neutralization of Input During Web Page Generation), commonly known as Cross-Site Scripting. The AT Internet SmartTag module for Drupal fails to properly sanitize user-supplied input before rendering it in web pages, creating an opportunity for attackers to inject malicious client-side scripts.

When exploited, an attacker can craft malicious input that, when processed by the vulnerable module, results in the execution of arbitrary JavaScript within the browser of any user viewing the affected page. This can occur through various injection points where the module handles analytics-related data or configuration parameters without adequate output encoding.

Root Cause

The root cause of this vulnerability lies in insufficient input validation and output encoding within the AT Internet SmartTag module. The module fails to properly neutralize special characters and HTML entities before including user-controlled data in dynamically generated web pages. This allows attackers to break out of the intended data context and inject executable script content.

Attack Vector

The attack vector for this XSS vulnerability typically involves an attacker injecting malicious payloads through module configuration fields, URL parameters, or other input vectors that the AT Internet SmartTag module processes. The vulnerability can manifest as either stored XSS (where the payload is persisted in the database) or reflected XSS (where the payload is immediately reflected in the response).

Exploitation does not require authentication in many XSS scenarios, and the attack can be delivered through crafted links sent to victims or through persistent injection if the attacker has access to content creation or configuration areas.

The vulnerability mechanism involves insufficient sanitization of analytics tracking parameters. When the SmartTag module processes certain inputs for page tracking purposes, malicious script content can bypass filters and be rendered directly in the HTML output. For detailed technical information, refer to the Drupal Security Advisory.

Detection Methods for CVE-2026-0946

Indicators of Compromise

• Unexpected JavaScript execution or browser alerts on pages using the AT Internet SmartTag module
• Presence of encoded script tags or JavaScript event handlers in module-related database fields or URL parameters
• User reports of suspicious redirects or credential harvesting attempts originating from affected Drupal pages

Detection Strategies

• Review web application firewall (WAF) logs for XSS attack patterns targeting Drupal sites with the AT Internet SmartTag module
• Implement Content Security Policy (CSP) headers and monitor for policy violations that may indicate XSS exploitation attempts
• Scan Drupal installations for the presence of AT Internet SmartTag module versions prior to 1.0.1

Monitoring Recommendations

• Enable detailed logging for the AT Internet SmartTag module to capture suspicious input patterns
• Monitor browser console errors and CSP reports from production Drupal sites for signs of script injection
• Implement real-time alerting for database modifications to SmartTag configuration tables

How to Mitigate CVE-2026-0946

Immediate Actions Required

• Update the AT Internet SmartTag module to version 1.0.1 or later immediately
• Audit existing SmartTag module configurations for any signs of injected malicious content
• Implement Content Security Policy headers to reduce the impact of any successful XSS exploitation

Patch Information

Drupal has released version 1.0.1 of the AT Internet SmartTag module to address this XSS vulnerability. Organizations should apply this update as soon as possible. The security advisory with patch details is available at the Drupal Security Advisory page.

Workarounds

• If immediate patching is not possible, consider temporarily disabling the AT Internet SmartTag module until the update can be applied
• Implement strict Content Security Policy headers with script-src directives to mitigate XSS impact
• Use a Web Application Firewall (WAF) with XSS filtering rules to block common injection attempts

# Example: Disable the AT Internet SmartTag module via Drush until patching is complete
drush pm:uninstall at_internet_smarttag

# Example: Update the module to the patched version
composer require drupal/at_internet_smarttag:^1.0.1
drush updatedb
drush cache:rebuild