CVE-2026-1824: Infomaniak Connect WordPress XSS Flaw

CVE-2026-1824 Overview

The Infomaniak Connect for OpenID plugin for WordPress contains a Stored Cross-Site Scripting (XSS) vulnerability in the endpoint_login parameter of the infomaniak_connect_generic_auth_url shortcode. This vulnerability exists in all versions up to and including 1.0.2 due to insufficient input sanitization and output escaping. Authenticated attackers with Contributor-level access or above can exploit this flaw to inject arbitrary web scripts into pages that execute whenever a user accesses the compromised page.

Critical Impact

Authenticated attackers can inject persistent malicious scripts that execute in the context of other users' sessions, potentially leading to credential theft, session hijacking, or further privilege escalation within the WordPress installation.

Affected Products

• Infomaniak Connect for OpenID WordPress Plugin version 1.0.2 and earlier
• WordPress sites utilizing the infomaniak_connect_generic_auth_url shortcode
• Any WordPress installation with Contributor-level or higher user accounts using this plugin

Discovery Timeline

• 2026-03-07 - CVE-2026-1824 published to NVD
• 2026-03-09 - Last updated in NVD database

Technical Details for CVE-2026-1824

Vulnerability Analysis

This Stored Cross-Site Scripting vulnerability is classified under CWE-79 (Improper Neutralization of Input During Web Page Generation). The vulnerability allows authenticated users with at least Contributor privileges to inject malicious JavaScript code through the endpoint_login parameter within the plugin's shortcode implementation.

The attack is network-based and requires low privileges to execute. Due to the stored nature of this XSS vulnerability, the injected payload persists in the database and executes every time a victim visits the affected page. The scope is changed, meaning the vulnerable component can impact resources beyond its security scope, affecting both confidentiality and integrity of user sessions.

Root Cause

The root cause lies in the insufficient input sanitization and output escaping within the shortcode handler located in openid-connect-infomaniak-client-wrapper.php. When processing the endpoint_login parameter, the plugin fails to properly sanitize user-supplied input before storing it and does not adequately escape the output when rendering the shortcode content on the page.

This allows malicious script content to be embedded within the parameter value and subsequently rendered as executable JavaScript in the browsers of users viewing the affected page. The vulnerable code can be reviewed at line 236 of the plugin source code.

Attack Vector

The attack vector requires network access and an authenticated session with at least Contributor-level privileges on the target WordPress installation. An attacker can craft a malicious shortcode containing JavaScript payloads in the endpoint_login parameter and embed it within a post or page.

When the content is saved and subsequently viewed by other users (including administrators), the malicious script executes in their browser context. This can lead to session token theft, unauthorized actions on behalf of the victim, defacement, or redirection to malicious sites. The vulnerability's persistent nature makes it particularly dangerous as it requires no further interaction from the attacker once the payload is deployed.

Detection Methods for CVE-2026-1824

Indicators of Compromise

• Unusual JavaScript content within posts or pages using the infomaniak_connect_generic_auth_url shortcode
• Unexpected <script> tags or event handlers within the endpoint_login parameter values in the WordPress database
• Browser console errors or unexpected network requests originating from pages using this shortcode
• User reports of suspicious behavior when viewing pages with OpenID Connect functionality

Detection Strategies

• Review WordPress posts and pages for malicious shortcode usage with suspicious endpoint_login values
• Implement Web Application Firewall (WAF) rules to detect XSS patterns in shortcode parameters
• Monitor WordPress audit logs for content modifications by Contributor-level users
• Scan the wp_posts table for entries containing potentially malicious script content within shortcode attributes

Monitoring Recommendations

• Enable WordPress activity logging to track content changes by authenticated users
• Deploy client-side XSS detection mechanisms that alert on unexpected script execution
• Regularly audit user accounts with Contributor or higher privileges for suspicious activity
• Implement Content Security Policy (CSP) headers to mitigate the impact of successful XSS attacks

How to Mitigate CVE-2026-1824

Immediate Actions Required

• Update the Infomaniak Connect for OpenID plugin to a version newer than 1.0.2 when a patched version becomes available
• Review and remove any suspicious content from posts or pages using the infomaniak_connect_generic_auth_url shortcode
• Audit Contributor-level user accounts and remove unnecessary elevated privileges
• Consider temporarily deactivating the plugin until a security patch is released

Patch Information

Monitor the WordPress Plugin Repository and Wordfence Vulnerability Report for updates on patched versions. Once available, update immediately through the WordPress admin dashboard or via WP-CLI.

Workarounds

• Restrict the use of the infomaniak_connect_generic_auth_url shortcode to trusted administrators only
• Implement strict Content Security Policy headers to limit script execution sources
• Use a WordPress security plugin with real-time XSS protection capabilities
• Temporarily demote Contributor accounts to Subscriber level until a patch is available

# Configuration example: Add CSP headers via .htaccess to mitigate XSS impact
# Add to WordPress root .htaccess file
<IfModule mod_headers.c>
    Header set Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none';"
    Header set X-XSS-Protection "1; mode=block"
    Header set X-Content-Type-Options "nosniff"
</IfModule>