CVE-2026-3003 Overview
CVE-2026-3003 is a Stored Cross-Site Scripting (XSS) vulnerability in the Vagaro Booking Widget plugin for WordPress. The flaw exists in the vagaro_code parameter and affects all plugin versions up to and including 0.3. The plugin fails to sanitize input and escape output, allowing unauthenticated attackers to inject arbitrary JavaScript into pages rendered by the plugin. Injected scripts execute in the browser of any visitor who loads an affected page. The issue is tracked under CWE-79.
Critical Impact
Unauthenticated attackers can inject persistent JavaScript that executes in visitor browsers, enabling session theft, redirection, and defacement of any WordPress site running the vulnerable plugin.
Affected Products
- Vagaro Booking Widget plugin for WordPress, versions 0.1 through 0.3
- WordPress sites with the plugin installed and activated
- Any page rendered by the plugin that processes the vagaro_code parameter
Discovery Timeline
- 2026-03-21 - CVE-2026-3003 published to NVD
- 2026-04-24 - Last updated in NVD database
Technical Details for CVE-2026-3003
Vulnerability Analysis
The Vagaro Booking Widget plugin accepts a vagaro_code parameter and renders it back into page output without sufficient sanitization or escaping. An attacker can submit crafted input containing HTML or JavaScript that the plugin stores and later emits inside the page response. When a user requests the page, the browser parses the attacker-controlled markup as part of the trusted document and executes the embedded script.
Because the attack vector is network-based and requires no authentication or user interaction beyond visiting a page, exploitation is straightforward. The scope change in the CVSS metric reflects that the injected script runs under the site's origin and can affect resources beyond the vulnerable component, including authenticated administrator sessions. The EPSS probability stands at 0.117% with a percentile of 30.0 as of 2026-05-14, indicating low but non-zero observed exploitation activity.
Root Cause
The vulnerability stems from missing input sanitization on the vagaro_code parameter and missing output escaping when the value is reflected into HTML. Standard WordPress helpers such as sanitize_text_field() for input and esc_attr() or esc_html() for output are not applied at the relevant code paths. Reviewers can examine the unsafe handling in the plugin source at lines 104 and 230.
Attack Vector
An unauthenticated attacker submits a payload containing JavaScript through the vagaro_code parameter. The plugin stores or reflects the payload into a rendered page. When a visitor or administrator loads that page, the browser executes the injected script in the site's origin. Typical objectives include stealing session cookies, performing actions on behalf of an administrator, redirecting users to attacker-controlled domains, or planting additional malicious content. Details are documented in the Wordfence Vulnerability Report.
Detection Methods for CVE-2026-3003
Indicators of Compromise
- Unexpected <script> tags, event handlers, or javascript: URIs appearing in pages rendered by the Vagaro Booking Widget plugin
- HTTP requests containing encoded JavaScript payloads in the vagaro_code parameter in web server access logs
- Outbound browser requests from site visitors to unknown third-party domains after loading pages containing the widget
- New or modified WordPress administrator accounts created shortly after suspicious requests to the plugin endpoint
Detection Strategies
- Inspect WordPress database tables and plugin options for stored values in vagaro_code containing HTML tags or script content
- Deploy a web application firewall rule that flags HTML special characters and script keywords in the vagaro_code parameter
- Review web server access logs for vagaro_code values containing URL-encoded <, >, script, onerror, or onload substrings
Monitoring Recommendations
- Enable Content Security Policy (CSP) reporting to surface inline script violations on pages containing the booking widget
- Monitor WordPress audit logs for unauthenticated POST requests touching plugin endpoints
- Alert on administrator session activity originating from unusual IP addresses following exposure to widget pages
How to Mitigate CVE-2026-3003
Immediate Actions Required
- Deactivate the Vagaro Booking Widget plugin on all WordPress sites until a patched version is published
- Audit pages that render the widget and remove any stored payloads containing scripts or HTML markup
- Force a password reset for WordPress administrator accounts that accessed widget pages during the exposure window
- Apply WAF rules that strip or block HTML and script content in the vagaro_code parameter
Patch Information
At the time of NVD publication on 2026-03-21, all versions up to and including 0.3 are listed as vulnerable. No fixed version is referenced in the available advisories. Monitor the WordPress plugin repository and the Wordfence Vulnerability Report for a release that adds proper sanitization and escaping.
Workarounds
- Uninstall the plugin and embed the Vagaro booking flow via an iframe to the vendor-hosted booking page instead
- Apply a CSP header that disallows inline scripts and restricts script sources to trusted origins
- Restrict access to pages containing the widget using authentication or IP allowlisting until a patch is available
# Configuration example: deactivate the plugin via WP-CLI
wp plugin deactivate vagaro-booking-widget
wp plugin uninstall vagaro-booking-widget
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
