CVE-2025-8690 Overview
CVE-2025-8690 is a stored Cross-Site Scripting (XSS) vulnerability in the Simple Responsive Slider plugin for WordPress. The flaw affects all versions of the addi-simple-slider plugin up to and including version 2.0. The plugin fails to properly sanitize input and escape output, allowing authenticated users with Contributor-level access or above to inject arbitrary JavaScript. Injected scripts execute in the browser of any user who visits an affected page, enabling session theft, credential harvesting, or forced administrative actions. The vulnerability is tracked under CWE-79 (Improper Neutralization of Input During Web Page Generation).
Critical Impact
Authenticated contributors can persist malicious JavaScript in WordPress pages that executes for every subsequent visitor, including administrators.
Affected Products
- WordPress plugin: Simple Responsive Slider (addi-simple-slider)
- All plugin versions up to and including 2.0
- WordPress installations where the plugin is active and Contributor accounts exist
Discovery Timeline
- 2025-08-12 - CVE-2025-8690 published to the National Vulnerability Database
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-8690
Vulnerability Analysis
The vulnerability resides in the Simple Responsive Slider plugin's handling of slider content submitted through its administrative interface. According to the Wordfence Vulnerability Report, the plugin's methods.php accepts user-supplied values without applying WordPress sanitization functions such as sanitize_text_field() and does not escape values on output using esc_attr() or esc_html().
Because the injected payload is stored in the database and rendered on front-end pages, this is a persistent XSS condition. Any visitor loading a compromised page executes the attacker's script under the site's origin. Attackers commonly leverage this to steal session cookies, pivot to administrator accounts, or drop cryptominers and redirect scripts.
Root Cause
The root cause is insufficient input sanitization combined with missing output escaping in the plugin's slide-management routines. Refer to the WordPress SVN Method File for the vulnerable code path. Data flows directly from request parameters into stored slider records and then into rendered HTML without neutralization of characters such as <, >, and quote marks.
Attack Vector
Exploitation requires an authenticated account with Contributor privileges or higher. The attacker submits crafted slider content containing HTML or JavaScript through the plugin's editing interface. When any user, including administrators, subsequently loads a page rendering the slider, the payload executes in the victim's browser session. The scope is changed because a low-privilege contributor can attack higher-privilege users, aligning with the CVSS scope-changed indicator.
No verified proof-of-concept code is publicly available.
See the Wordfence advisory for technical details on the vulnerable input handlers.
Detection Methods for CVE-2025-8690
Indicators of Compromise
- Slider records or post metadata containing <script>, onerror=, onload=, or javascript: sequences
- Unexpected outbound requests from browser sessions loading pages that embed the slider
- New or modified WordPress administrator accounts following contributor activity
- Contributor accounts editing slider content at unusual hours or from unexpected IP addresses
Detection Strategies
- Inspect the wp_posts and wp_postmeta tables for slider entries containing HTML event handlers or <script> tags
- Review WordPress access logs for POST requests to admin-ajax.php or plugin endpoints from Contributor accounts
- Deploy a Web Application Firewall rule that flags XSS payloads in requests targeting the addi-simple-slider plugin paths
Monitoring Recommendations
- Enable WordPress audit logging to capture content edits by Contributor and Author roles
- Alert on newly created administrator accounts and role changes
- Monitor Content Security Policy violation reports for inline script execution on pages that host sliders
How to Mitigate CVE-2025-8690
Immediate Actions Required
- Deactivate the Simple Responsive Slider plugin until a patched release is confirmed by the maintainer
- Audit all existing slider content for injected HTML, scripts, or event handler attributes and remove malicious entries
- Review and rotate credentials for any WordPress accounts that may have been targeted through XSS payloads
- Restrict the Contributor role assignment to trusted users only
Patch Information
At the time of publication, no fixed version beyond 2.0 is documented in the Wordfence Vulnerability Report. Administrators should monitor the WordPress Plugin Developer Docs for release notes and apply an updated version as soon as one becomes available.
Workarounds
- Remove the plugin entirely if no vendor patch is forthcoming
- Enforce a strict Content Security Policy that disallows inline scripts and unauthorized script sources
- Restrict the unfiltered_html capability and avoid granting elevated roles to untrusted contributors
- Place the WordPress admin surface behind a Web Application Firewall configured to block stored XSS payloads
# Disable the vulnerable plugin using WP-CLI
wp plugin deactivate addi-simple-slider
wp plugin delete addi-simple-slider
# Search the database for potentially injected slider content
wp db query "SELECT ID, post_title FROM wp_posts WHERE post_content LIKE '%<script%' OR post_content LIKE '%onerror=%';"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
