CVE-2026-39642 Overview
CVE-2026-39642 is a Basic Cross-Site Scripting (XSS) vulnerability in the SpabRice Nyla WordPress theme. The flaw stems from improper neutralization of script-related HTML tags in a web page, allowing attackers to inject malicious code. The vulnerability affects Nyla versions from an unspecified initial release through 1.7. It is also referenced in advisories as an arbitrary shortcode execution issue in the Nyla theme. The weakness is classified under [CWE-80] (Improper Neutralization of Script-Related HTML Tags).
Critical Impact
Remote, unauthenticated attackers can inject script content into pages rendered by the Nyla theme, leading to information disclosure in the browsers of victims who view affected pages.
Affected Products
- SpabRice Nyla WordPress theme
- Nyla versions through 1.7
- WordPress sites using the vulnerable Nyla theme
Discovery Timeline
- 2026-05-26 - CVE-2026-39642 published to NVD
- 2026-05-26 - Last updated in NVD database
Technical Details for CVE-2026-39642
Vulnerability Analysis
The Nyla theme fails to neutralize script-related HTML tags before rendering user-controllable input within a web page. An unauthenticated attacker can deliver a crafted payload over the network and trigger script execution in the context of the affected site. Because the issue is exposed through a WordPress theme, it is reachable through standard HTTP requests to public pages or endpoints that surface the unsanitized data. The vendor advisory describes the underlying mechanism as arbitrary shortcode execution, where shortcode processing can be abused to emit attacker-controlled markup, including <script> tags, into rendered output.
Root Cause
The root cause is missing or insufficient output encoding and input sanitization on script-related HTML tags within the theme's rendering path. Inputs that should be treated as inert text are instead interpreted as active HTML, allowing <script> and related elements to pass through. This is a textbook [CWE-80] basic XSS pattern, made reachable through the theme's shortcode handling.
Attack Vector
The vulnerability is exploitable over the network with low attack complexity and no privileges or user interaction beyond visiting an affected page. An attacker crafts input containing script-related HTML and submits it through any entry point that feeds the vulnerable shortcode or rendering function. When the page is served, the injected payload executes in the browser of any visitor, enabling theft of session data, redirection, or further client-side abuse. Refer to the Patchstack Vulnerability Advisory for technical specifics on the affected shortcode path.
// No verified exploitation code is published for CVE-2026-39642.
// See the Patchstack advisory linked above for technical details.
Detection Methods for CVE-2026-39642
Indicators of Compromise
- Unexpected <script> tags, javascript: URIs, or HTML event handlers stored in WordPress post content, options, or shortcode attributes.
- Outbound browser requests from site visitors to unfamiliar domains shortly after loading pages that use Nyla shortcodes.
- New or modified administrator accounts following visits by privileged users to pages rendered by the Nyla theme.
Detection Strategies
- Inspect rendered HTML on pages built with the Nyla theme for script content that did not originate from trusted plugins or theme files.
- Review WordPress database tables (wp_posts, wp_postmeta, wp_options) for shortcode attributes containing HTML or script payloads.
- Apply web application firewall (WAF) rules that flag XSS patterns in requests targeting WordPress endpoints serving Nyla content.
Monitoring Recommendations
- Enable WordPress audit logging to capture content changes, shortcode usage, and administrative actions.
- Monitor HTTP access logs for requests containing encoded <script> payloads or suspicious shortcode parameters.
- Alert on Content Security Policy (CSP) violation reports indicating inline script execution on Nyla-rendered pages.
How to Mitigate CVE-2026-39642
Immediate Actions Required
- Identify all WordPress installations running the SpabRice Nyla theme at version 1.7 or earlier.
- Disable the Nyla theme on affected sites until a patched version is applied, or switch to an alternative theme.
- Audit existing post content, widgets, and theme options for previously injected script payloads and remove them.
Patch Information
No fixed version is identified in the available CVE data. Administrators should consult the Patchstack Vulnerability Advisory for the latest remediation guidance and apply any update released by SpabRice for versions later than 1.7.
Workarounds
- Restrict shortcode usage to trusted authors and remove the vulnerable shortcode from public-facing input paths.
- Deploy a WAF rule set that blocks XSS payloads targeting WordPress theme endpoints.
- Implement a strict Content Security Policy that disallows inline scripts and unapproved script sources.
# Example: enforce a restrictive Content-Security-Policy header via Apache
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'; frame-ancestors 'self'"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
