CVE-2026-76562 Overview
The Sidebar Manager Light plugin for WordPress contains a Stored Cross-Site Scripting (XSS) vulnerability in the sbm_description parameter. The flaw affects all versions up to and including 1.18. The plugin fails to sanitize input and escape output, allowing unauthenticated attackers to inject arbitrary JavaScript that executes when any user views an affected page. The issue is tracked as [CWE-79] Improper Neutralization of Input During Web Page Generation.
Critical Impact
Unauthenticated attackers can inject persistent JavaScript payloads that execute in the browser of any visitor, enabling session theft, administrative account compromise, and drive-by redirection.
Affected Products
- WordPress Sidebar Manager Light plugin versions 1.0 through 1.18
- WordPress sites with the plugin activated
- All site visitors and authenticated administrators viewing injected sidebar content
Discovery Timeline
- 2026-09-10 - CVE-2026-76562 published to the National Vulnerability Database (NVD)
- 2026-09-10 - Last updated in NVD database
Technical Details for CVE-2026-76562
Vulnerability Analysis
The vulnerability is a Stored Cross-Site Scripting flaw in the Sidebar Manager Light plugin. The sbm_description parameter is written to the database and later rendered without proper output encoding. Because the injection is persistent, the payload executes for every user who loads a page containing the affected sidebar description.
Exploitation requires no authentication and no user interaction beyond visiting the injected page. The scope change reflected in the CVSS metric indicates the payload runs in a security context different from the vulnerable component, executing in the browsers of administrators and regular visitors alike.
Root Cause
The plugin does not apply input sanitization functions such as sanitize_text_field() or wp_kses() when storing the sbm_description value. It also fails to apply output escaping such as esc_html() or esc_attr() when rendering the description in sidebar output. Relevant sink locations are visible in the plugin source at include/otw_list_sidebars.php line 93 and include/otw_process_actions.php lines 89 and 139, referenced in the WordPress Plugin Trac.
Attack Vector
An attacker submits a crafted request containing JavaScript within the sbm_description parameter to a vulnerable endpoint handled by otw_process_actions.php. The malicious content persists in the WordPress database. When an administrator or visitor loads a page rendering the sidebar, the browser executes the script. Common outcomes include stealing authentication cookies, creating rogue administrator accounts, injecting SEO spam, or redirecting users to attacker-controlled infrastructure. See the Wordfence Vulnerability Report for additional technical context.
Detection Methods for CVE-2026-76562
Indicators of Compromise
- Unexpected <script>, <iframe>, or on* event handler attributes in stored sidebar description records within the WordPress database
- New or modified administrator accounts created shortly after unauthenticated POST requests to plugin action endpoints
- Outbound requests from visitor sessions to unfamiliar third-party domains after loading pages that render sidebars
Detection Strategies
- Query the wp_options and plugin-specific tables for entries containing HTML tags or JavaScript keywords in the sbm_description field
- Review web server access logs for POST requests to otw_process_actions.php with suspicious payloads in the sbm_description parameter
- Deploy web application firewall (WAF) rules that inspect request bodies for script injection patterns targeting the plugin endpoints
Monitoring Recommendations
- Alert on file integrity changes within wp-content/plugins/sidebar-manager-light/
- Monitor for unauthenticated requests to plugin AJAX or admin-post actions from unusual source addresses
- Track browser Content Security Policy (CSP) violation reports for inline script executions originating on sidebar-rendered pages
How to Mitigate CVE-2026-76562
Immediate Actions Required
- Deactivate the Sidebar Manager Light plugin until a patched version is confirmed installed
- Audit stored sidebar descriptions for existing injected payloads and remove any malicious content
- Rotate WordPress administrator credentials and invalidate active sessions if injection is confirmed
Patch Information
No patched version is referenced in the currently available advisory data. Site operators should monitor the Wordfence Vulnerability Report and the plugin repository on WordPress.org for a release beyond version 1.18 that addresses the input sanitization and output escaping gaps.
Workarounds
- Remove or disable the Sidebar Manager Light plugin from all WordPress installations until a fixed release is available
- Deploy WAF signatures that block requests containing HTML or JavaScript tokens in the sbm_description parameter
- Enforce a strict Content Security Policy that disallows inline scripts to limit the impact of stored payloads
# Example WAF rule (ModSecurity) blocking script content in sbm_description
SecRule ARGS:sbm_description "@rx (?i)(<script|onerror=|onload=|javascript:)" \
"id:1026762,phase:2,deny,status:403,msg:'Blocked XSS attempt targeting CVE-2026-76562'"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
