CVE-2026-18562 Overview
CVE-2026-18562 is a Reflected Cross-Site Scripting (XSS) vulnerability in the HUSKY – Products Filter Professional for WooCommerce plugin for WordPress. The flaw affects all versions up to and including 1.4.3. Unauthenticated attackers can inject arbitrary JavaScript through SEO-friendly permalink filter URL segments. Successful exploitation requires user interaction, such as clicking a specially crafted link. The vulnerability is classified as Improper Neutralization of Input During Web Page Generation [CWE-79].
Critical Impact
Attackers can execute arbitrary JavaScript in the context of a victim's browser session, enabling session hijacking, credential theft, or redirection to attacker-controlled infrastructure on affected WooCommerce storefronts.
Affected Products
- HUSKY – Products Filter Professional for WooCommerce plugin for WordPress
- All versions up to and including 1.4.3
- WordPress sites running WooCommerce with the vulnerable plugin enabled
Discovery Timeline
- 2026-09-11 - CVE-2026-18562 published to NVD
- 2026-09-11 - Last updated in NVD database
Technical Details for CVE-2026-18562
Vulnerability Analysis
The vulnerability resides in the wp_load_js() function of the HUSKY plugin. This function reads filter values from the URL path through the url_request extension's parse_url_query() method. The values are then embedded into an inline JavaScript string using json_encode() without escaping single quotes.
Because json_encode() by default does not escape single quote characters, an attacker-supplied value placed inside a single-quoted JavaScript string literal can break out of the string context. Once the string context is broken, attacker-controlled input is parsed as executable JavaScript by the browser.
The attack requires only a crafted URL and social engineering to trigger execution. No authentication is required, and the payload executes with the privileges of the victim's WordPress session.
Root Cause
The root cause is insufficient input sanitization and output escaping when constructing inline JavaScript. The plugin trusts URL path segments parsed by parse_url_query() in ext/url_request/classes/url_parser.php and reflects them into a <script> block in index.php around line 1116. Missing the JSON_HEX_APOS flag on json_encode() allows single quotes to escape the string literal.
Attack Vector
An unauthenticated remote attacker crafts a malicious URL containing filter path segments with an embedded single quote followed by JavaScript. When a victim clicks the link on a vulnerable WooCommerce site, the plugin reflects the payload into an inline script block on the rendered page. The browser then executes the injected code within the site's origin.
Technical references for the vulnerable code paths are available in the WordPress URL Parser source and the plugin index handler.
Detection Methods for CVE-2026-18562
Indicators of Compromise
- Access log entries containing URL path segments with encoded or literal single quote characters (%27 or ') within HUSKY filter permalink segments.
- Requests to WooCommerce category or shop pages containing unexpected JavaScript keywords such as alert(, onerror=, <script, or document.cookie in filter path segments.
- Outbound requests from user browsers to unfamiliar external domains immediately following visits to product filter pages.
Detection Strategies
- Deploy Web Application Firewall (WAF) rules that inspect request URIs for XSS payload patterns targeting HUSKY filter routes.
- Review server access logs for anomalous filter URL structures containing quote characters, angle brackets, or JavaScript event handlers.
- Correlate referrer headers pointing to external sites with subsequent suspicious client-side activity on the WooCommerce store.
Monitoring Recommendations
- Enable Content Security Policy (CSP) reporting to capture script-src violations that indicate reflected injection attempts.
- Monitor administrator accounts for anomalous session activity, plugin changes, or new user creation following suspected XSS delivery.
- Alert on outbound HTTP requests from WordPress admin sessions to newly observed or low-reputation domains.
How to Mitigate CVE-2026-18562
Immediate Actions Required
- Update the HUSKY – Products Filter Professional for WooCommerce plugin to a version newer than 1.4.3 as soon as a patched release is available.
- Audit WooCommerce sites to inventory instances of the plugin and confirm version status.
- Force logout of privileged sessions and rotate administrator credentials if compromise is suspected.
Patch Information
The vendor addressed the vulnerability in a code change tracked as WordPress Change Set #3640571. Site administrators should apply the plugin update through the WordPress plugin manager. Additional details are documented in the Wordfence Vulnerability Report.
Workarounds
- Disable the HUSKY – Products Filter Professional plugin until the patched version can be applied.
- Deploy a WAF rule that blocks or sanitizes single quote characters and script tags within HUSKY filter URL path segments.
- Implement a strict Content Security Policy that disallows inline script execution to reduce the impact of reflected XSS payloads.
- Educate staff and customers to avoid clicking untrusted links targeting the store domain.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
