CVE-2026-57762: Simple URLs XSS Vulnerability

CVE-2026-57762 Overview

CVE-2026-57762 is a stored Cross-Site Scripting (XSS) vulnerability [CWE-79] affecting the Simple URLs WordPress plugin in versions 151 and earlier. The flaw allows authenticated users with Author-level privileges to inject malicious scripts into plugin-managed content. Successful exploitation executes attacker-controlled JavaScript in the context of other users' browsers, including administrators. The scope-changed CVSS vector indicates that the injected payload affects components beyond the vulnerable plugin, such as the WordPress administrative interface.

Critical Impact
Author-level accounts can inject persistent JavaScript that executes in higher-privileged users' sessions, enabling session theft, administrative action forgery, and content tampering across the affected WordPress site.

Affected Products

Simple URLs WordPress plugin, versions 151 and earlier
WordPress installations with the Simple URLs plugin activated
Sites permitting untrusted Author-level account registration

Discovery Timeline

2026-07-02 - CVE-2026-57762 published to NVD
2026-07-02 - Last updated in NVD database

Technical Details for CVE-2026-57762

Vulnerability Analysis

The vulnerability resides in the Simple URLs plugin's handling of user-supplied input in fields accessible to Author-level users. The plugin fails to sanitize or escape input before rendering it in HTML contexts. When an administrator or other user views the affected page, the injected script executes with the viewer's privileges.

The scope-changed rating reflects that the payload crosses a security boundary. Author accounts have limited native WordPress permissions, but the injected script runs against the administrative interface. This enables privilege escalation through session hijacking or forged administrative requests.

The attack requires user interaction, meaning a higher-privileged user must view the malicious content. In practice, administrators routinely review author-generated content, making the interaction requirement a modest barrier.

Root Cause

The root cause is improper neutralization of input during web page generation [CWE-79]. The plugin accepts input from Author-role users and stores it without applying WordPress escaping functions such as esc_html(), esc_attr(), or wp_kses() before output. This allows raw HTML and JavaScript to reach the rendered DOM.

Attack Vector

An attacker requires an authenticated Author-level account on the target WordPress site. The attacker submits a crafted payload through a Simple URLs plugin input field. When an administrator or editor views the page containing the payload, the JavaScript executes in their browser session. The attacker can then perform actions such as creating administrator accounts, exfiltrating nonces, or modifying site content.

No verified public exploit code is available for CVE-2026-57762. See the Patchstack XSS Vulnerability Report for technical details on the affected input handling.

Detection Methods for CVE-2026-57762

Indicators of Compromise

Unexpected <script> tags, event handlers such as onerror or onload, or javascript: URIs stored in Simple URLs plugin database tables
New WordPress administrator accounts created without corresponding audit trail entries
Outbound HTTP requests from administrator browsers to unfamiliar domains after viewing plugin-managed pages
Modifications to plugin or theme files following administrator sessions

Detection Strategies

Query the WordPress database for Simple URLs entries containing HTML tags, <script, or common XSS keywords such as onerror=, onclick=, or eval(
Deploy a Web Application Firewall (WAF) with WordPress-aware rules that inspect POST requests to plugin admin endpoints for script payloads
Enable Content Security Policy (CSP) headers in report-only mode to surface inline script violations originating from plugin content

Monitoring Recommendations

Log all WordPress user role changes and administrator account creation events
Monitor the wp_users and wp_usermeta tables for unauthorized modifications
Alert on authenticated sessions where an Author-role user submits input containing HTML entities that decode to script tags
Review web server access logs for administrative requests originating from Author-role session cookies

How to Mitigate CVE-2026-57762

Immediate Actions Required

Update the Simple URLs plugin to a version above 151 as soon as the vendor releases a patched release
Audit existing Author-level accounts and remove any that are unrecognized or inactive
Review Simple URLs plugin content for stored payloads and remove malicious entries
Rotate WordPress administrator credentials and invalidate active sessions if compromise is suspected

Patch Information

Refer to the Patchstack XSS Vulnerability Report for the current patch status. Apply the vendor-supplied update through the WordPress plugin management console once available.

Workarounds

Deactivate the Simple URLs plugin until a patched version is installed
Restrict Author-role assignment to trusted users and disable open user registration
Implement a WAF rule that blocks HTML tags in POST parameters targeting Simple URLs admin endpoints
Enforce a strict Content Security Policy that disallows inline scripts in the WordPress admin area

bash

# Configuration example: restrict WordPress user registration and enforce CSP
wp option update users_can_register 0
wp option update default_role subscriber

# Add CSP header via web server (nginx example)
add_header Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none';" always;