CVE-2026-15082 Overview
CVE-2026-15082 is a stored Cross-Site Scripting (XSS) vulnerability in the Drupal Siteimprove Analytics contributed module. The flaw stems from improper neutralization of input during web page generation, classified under [CWE-79]. It affects Siteimprove Analytics versions 0.0.0 through 2.0.1. An authenticated attacker with low privileges can inject script content that executes in the browsers of users interacting with affected pages. Exploitation requires user interaction and produces a scope change, meaning injected scripts can impact resources beyond the vulnerable component. The issue is documented in the Drupal Security Advisory SA-CONTRIB-2026-073.
Critical Impact
Authenticated attackers can inject persistent scripts that execute in administrator or editor browsers, enabling session theft, forced actions, and content manipulation on the Drupal site.
Affected Products
- Drupal Siteimprove Analytics module version 0.0.0 through 2.0.1
- Drupal sites with the Siteimprove Analytics integration enabled
- Administrative and editorial workflows that render analytics-provided content
Discovery Timeline
- 2026-07-10 - CVE-2026-15082 published to NVD
- 2026-07-13 - Last updated in NVD database
Technical Details for CVE-2026-15082
Vulnerability Analysis
The Siteimprove Analytics module integrates the Siteimprove SaaS analytics service into Drupal site administration. The vulnerability arises because input processed by the module is rendered into HTML without adequate output encoding or sanitization. As a result, an attacker with authenticated access can supply crafted values that Drupal later renders as executable script within a privileged user's session.
Because the flaw involves a scope change, script execution can reach content or actions outside the module's own security context. Typical outcomes include theft of authenticated session data, unauthorized configuration changes, and abuse of the site's administrative APIs. The vulnerability requires user interaction, which usually means a target must load an administrative page that renders the attacker-controlled value.
Root Cause
The root cause is missing or incomplete neutralization of user-supplied input before it is embedded in generated HTML output. Drupal provides rendering helpers, filter formats, and Twig auto-escaping to prevent this class of issue, but the affected code paths in Siteimprove Analytics do not consistently apply them. Any attacker-controlled string that reaches the DOM without proper encoding becomes a candidate injection sink.
Attack Vector
The attack vector is network-based and requires an account with low privileges on the Drupal site. The attacker submits crafted payloads through fields or parameters exposed by the module. When a privileged user later views a page that renders the stored data, the browser interprets the injected markup as script. The result is client-side code execution under the target user's origin and authenticated session.
No verified exploit code is publicly available. Refer to the vendor advisory for technical specifics.
Detection Methods for CVE-2026-15082
Indicators of Compromise
- Unexpected <script> tags, on* event handler attributes, or javascript: URIs stored in Drupal database fields associated with the Siteimprove Analytics module.
- Administrative user sessions performing actions from unusual IP addresses or user agents after loading analytics-related pages.
- Outbound requests from administrator browsers to unrecognized domains shortly after accessing the Drupal admin UI.
Detection Strategies
- Review Drupal watchdog and web server logs for POST requests to Siteimprove Analytics configuration endpoints containing HTML or script characters.
- Query stored configuration and content tables for suspicious tokens such as <script, onerror=, or javascript: in fields written by the module.
- Enable and monitor a strict Content Security Policy (CSP) report-only endpoint to surface script executions from unexpected sources.
Monitoring Recommendations
- Alert on new or modified Drupal user accounts, permission changes, or module installations following admin sessions on affected sites.
- Correlate authentication events for privileged Drupal roles with anomalous browser telemetry such as new outbound domains.
- Track access to /admin/config/system/siteimprove and related module paths for unusual write patterns.
How to Mitigate CVE-2026-15082
Immediate Actions Required
- Upgrade the Siteimprove Analytics module to a version later than 2.0.1 as published in the Drupal security advisory.
- Audit all users with permissions to configure the module and remove access that is not required.
- Inspect stored module configuration and content for injected markup and remove any suspicious values.
- Rotate session cookies and administrative credentials if unauthorized access is suspected.
Patch Information
Drupal has published remediation guidance in SA-CONTRIB-2026-073. Apply the fixed release identified in that advisory. After upgrading, clear Drupal caches and verify that module output is rendered through Drupal's standard sanitization pipeline.
Workarounds
- Temporarily disable the Siteimprove Analytics module until the patched version is deployed.
- Restrict the roles allowed to configure the module to trusted administrators only.
- Deploy a strict Content Security Policy that disallows inline scripts and restricts script sources to trusted origins.
- Place the Drupal administrative interface behind a web application firewall rule set that inspects requests for XSS payloads.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
