CVE-2025-49858 Overview
CVE-2025-49858 is a stored cross-site scripting (XSS) vulnerability in the Arconix Shortcodes WordPress plugin developed by tychesoftwares. The flaw affects all versions up to and including 2.1.17. An authenticated attacker with low-level privileges can inject malicious JavaScript that persists within the application and executes in the browser of any user who views the affected content. The vulnerability maps to CWE-79, Improper Neutralization of Input During Web Page Generation.
Critical Impact
Authenticated contributors can store malicious scripts that execute against site administrators and visitors, enabling session theft, account takeover, and arbitrary actions in the WordPress admin context.
Affected Products
- tychesoftwares Arconix Shortcodes plugin for WordPress
- All versions from n/a through 2.1.17
- WordPress sites with the plugin installed and active
Discovery Timeline
- 2025-06-17 - CVE-2025-49858 published to the National Vulnerability Database
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-49858
Vulnerability Analysis
The vulnerability resides in how the Arconix Shortcodes plugin processes user-supplied input before rendering it inside WordPress pages and posts. The plugin fails to properly neutralize script content passed through shortcode attributes or associated input fields. The stored nature of the flaw means the malicious payload is persisted in the WordPress database. Every subsequent request that loads the affected content executes the attacker's JavaScript in the victim's browser session.
The scope change reflected in the vulnerability's CVSS vector indicates that the injected script can affect resources beyond the vulnerable component. In a WordPress context, this typically means an administrator viewing an infected post can have their authenticated session abused to create new admin users, modify site content, or install additional plugins.
Root Cause
The root cause is missing or insufficient output encoding and input sanitization in the plugin's shortcode rendering logic. Standard WordPress functions such as esc_html(), esc_attr(), and wp_kses() are either not applied or applied incorrectly before user-controlled content is embedded in the HTML response. This allows raw HTML and JavaScript to pass through to the browser.
Attack Vector
Exploitation requires an authenticated account with privileges to publish or edit content containing shortcodes, typically a contributor, author, or editor role. The attacker crafts a shortcode containing a JavaScript payload within an attribute or parameter that the plugin fails to sanitize. User interaction is required: a victim, often an administrator or site visitor, must load the page or post containing the malicious shortcode. Once rendered, the script executes with the victim's privileges in the WordPress origin.
Technical details for the specific injection point are available in the Patchstack XSS Vulnerability Advisory.
Detection Methods for CVE-2025-49858
Indicators of Compromise
- Posts, pages, or widget content containing Arconix shortcodes with <script>, onerror=, onload=, or javascript: payloads in attribute values
- Unexpected administrator accounts created shortly after an authenticated user edits content
- Outbound HTTP requests from administrator browsers to unfamiliar domains while viewing WordPress admin pages
- Modifications to WordPress options, themes, or plugins without a corresponding admin action in audit logs
Detection Strategies
- Query the wp_posts and wp_postmeta tables for Arconix shortcode patterns combined with HTML event handlers or script tags
- Review web server logs for POST requests to /wp-admin/post.php and /wp-admin/admin-ajax.php containing encoded script payloads
- Deploy a web application firewall rule that flags shortcode attributes containing script delimiters
- Monitor for new WordPress user creation events that are not preceded by legitimate admin UI navigation
Monitoring Recommendations
- Enable WordPress audit logging to track content edits, user role changes, and plugin installations
- Alert on changes to high-privilege accounts and on creation of accounts with the administrator role
- Baseline normal shortcode usage across the site and alert on anomalous attribute content
How to Mitigate CVE-2025-49858
Immediate Actions Required
- Audit all installed WordPress plugins and identify sites running Arconix Shortcodes 2.1.17 or earlier
- Restrict content authoring privileges to trusted users while a patched version is unavailable
- Review existing posts, pages, and widgets for shortcode content containing script payloads and remove suspicious entries
- Rotate administrator credentials and invalidate active sessions if exploitation is suspected
Patch Information
At the time of publication, the Patchstack advisory lists versions through 2.1.17 as affected and does not reference a fixed release. Monitor the Patchstack XSS Vulnerability Advisory and the plugin page for an updated release that remediates the sanitization defect.
Workarounds
- Deactivate and remove the Arconix Shortcodes plugin until a patched version is published
- Deploy a web application firewall policy that blocks requests containing script tags or JavaScript event handlers inside shortcode attributes
- Apply Content Security Policy (CSP) headers that disallow inline scripts, reducing the impact of successful XSS injection
- Reduce the number of accounts with edit_posts or higher capability to limit the exploitation surface
# Example WordPress CLI command to disable the vulnerable plugin
wp plugin deactivate arconix-shortcodes
wp plugin delete arconix-shortcodes
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
