CVE-2025-11883 Overview
The Responsive Progress Bar plugin for WordPress contains a stored Cross-Site Scripting (XSS) vulnerability in versions less than or equal to 1.0. The flaw resides in the plugin's rprogress shortcode, which fails to sanitize user-supplied attributes or escape output. Authenticated attackers with contributor-level access or above can inject arbitrary JavaScript into pages. The injected script executes in the browser of any user who views the affected page, including administrators. The vulnerability is classified under CWE-79 (Improper Neutralization of Input During Web Page Generation).
Critical Impact
Authenticated contributors can inject persistent JavaScript that executes against site visitors and administrators, enabling session theft, account takeover, and administrative action forgery.
Affected Products
- Responsive Progress Bar plugin for WordPress, versions ≤ 1.0
- WordPress sites permitting contributor-level user registration
- Any WordPress deployment using the rprogress shortcode
Discovery Timeline
- 2025-10-22 - CVE-2025-11883 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-11883
Vulnerability Analysis
The vulnerability originates in the rprogress shortcode handler within responsive-progress-bar.php. The shortcode accepts user-supplied attributes and renders them directly into HTML output without sanitization or escaping. Because WordPress evaluates shortcodes when posts are rendered, malicious attribute values persist in stored content and execute for every subsequent viewer.
Contributor-level accounts can author draft posts containing shortcodes. When an editor or administrator previews or publishes the content, the injected payload runs in their authenticated session context. This turns a low-privilege account into a stepping stone for privilege escalation via administrative action hijacking.
Root Cause
The shortcode callback in the plugin echoes attribute values into HTML output without applying WordPress escaping functions such as esc_attr(), esc_html(), or wp_kses(). Neither shortcode_atts() filtering nor output encoding is applied to the user-controlled attribute set, allowing raw HTML and JavaScript to pass through.
Attack Vector
An authenticated attacker with contributor privileges submits a post containing the rprogress shortcode with malicious attribute values. The payload can include HTML event handlers or <script> fragments embedded within attribute strings. When the post is viewed by any authenticated user, the browser parses and executes the injected script under the site's origin.
Because the scope changes (CVSS S:C), the impact extends beyond the vulnerable component to any browser rendering the page. Typical post-exploitation actions include stealing authentication cookies, issuing REST API calls under an administrator session, and planting persistent backdoors via plugin or theme editing.
See the WordPress plugin source for the vulnerable shortcode implementation and the Wordfence advisory for additional detail.
Detection Methods for CVE-2025-11883
Indicators of Compromise
- Post or page content containing [rprogress ...] shortcodes with attribute values that include <, >, ", ', javascript:, or event handlers such as onerror= and onload=
- Unexpected outbound requests from browsers visiting affected pages to attacker-controlled domains
- New administrator accounts, modified user roles, or altered plugin and theme files created shortly after contributor activity
- Session cookies observed in web server access logs being reused from atypical IP addresses
Detection Strategies
- Query the wp_posts table for post_content matching the rprogress shortcode combined with script-related tokens
- Review WordPress audit logs for contributor accounts submitting posts for review immediately followed by administrator previews
- Inspect Content Security Policy violation reports for inline script execution on pages containing the plugin's shortcode
Monitoring Recommendations
- Enable a web application firewall with XSS signature coverage in front of /wp-admin/ and public post URLs
- Monitor administrative session activity for anomalous REST API calls to /wp/v2/users and /wp/v2/plugins
- Alert on plugin file modifications and unexpected creation of privileged accounts
How to Mitigate CVE-2025-11883
Immediate Actions Required
- Deactivate and remove the Responsive Progress Bar plugin until a patched release is available
- Audit all posts and pages for existing rprogress shortcode usage and remove any with suspicious attribute content
- Restrict contributor account registration and review the legitimacy of existing contributor-level users
- Rotate administrator credentials and invalidate active sessions if the plugin has been in use
Patch Information
No fixed version is listed in the NVD entry at time of publication. All versions less than or equal to 1.0 remain vulnerable. Monitor the plugin page on WordPress.org and the Wordfence advisory for updates.
Workarounds
- Remove the plugin entirely if the progress bar functionality is not business-critical
- Restrict the unfiltered_html capability and enforce the principle of least privilege for contributor and author roles
- Deploy a Content Security Policy that disallows inline scripts to reduce the impact of stored XSS payloads
- Configure a WAF rule to block shortcode attribute values containing <script, javascript:, or on*= event handlers in POST requests to /wp-admin/post.php
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
