CVE-2026-25399: Serious Slider Auth Bypass Vulnerability

CVE-2026-25399 Overview

A Missing Authorization vulnerability has been identified in the CryoutCreations Serious Slider WordPress plugin (cryout-serious-slider). This security flaw allows attackers to exploit incorrectly configured access control security levels, potentially enabling unauthorized actions within the plugin's functionality. The vulnerability stems from insufficient authorization checks (CWE-862) that fail to properly validate user permissions before executing sensitive operations.

Critical Impact

Authenticated attackers with low-level privileges can exploit broken access control to perform unauthorized actions, potentially leading to denial of service conditions on affected WordPress installations.

Affected Products

• CryoutCreations Serious Slider plugin versions up to and including 1.2.7
• WordPress installations with the cryout-serious-slider plugin active
• All WordPress versions running the vulnerable Serious Slider versions

Discovery Timeline

• 2026-02-19 - CVE-2026-25399 published to NVD
• 2026-02-19 - Last updated in NVD database

Technical Details for CVE-2026-25399

Vulnerability Analysis

This vulnerability represents a Broken Access Control flaw where the Serious Slider plugin fails to implement proper authorization checks for certain functionality. The missing authorization allows authenticated users to perform actions that should be restricted to higher-privileged roles, such as administrators. This type of vulnerability is particularly concerning in WordPress environments where multiple user roles (subscribers, contributors, authors, editors) may have legitimate access to the dashboard but should not have access to plugin management functions.

The attack requires network access and low-privilege authentication, meaning an attacker needs at least a basic WordPress account to exploit this vulnerability. No user interaction is required for successful exploitation, and while the scope remains unchanged, the vulnerability can lead to availability impacts on the affected system.

Root Cause

The root cause of CVE-2026-25399 is classified under CWE-862 (Missing Authorization). The Serious Slider plugin versions through 1.2.7 fail to implement proper capability checks before processing certain requests. In WordPress, authorization should be enforced using functions like current_user_can() to verify that the requesting user has appropriate capabilities for the action being performed. The absence of these checks allows any authenticated user to access functionality that should be restricted to administrators or editors only.

Attack Vector

The attack vector for this vulnerability is network-based, requiring the attacker to have low-level authenticated access to the WordPress installation. The exploitation scenario involves:

1. An attacker obtains or creates a low-privilege WordPress account (e.g., subscriber role)
2. The attacker identifies AJAX endpoints or administrative functions within the Serious Slider plugin that lack proper authorization checks
3. By crafting requests to these unprotected endpoints, the attacker can manipulate slider content or plugin settings
4. This can result in denial of service conditions affecting the availability of slider functionality

The vulnerability is straightforward to exploit once an authenticated session is established, as no special conditions or complex attack chains are required. For detailed technical information, refer to the Patchstack Vulnerability Advisory.

Detection Methods for CVE-2026-25399

Indicators of Compromise

• Unexpected modifications to slider content or settings by non-administrator users
• WordPress audit logs showing slider-related actions from unauthorized user roles
• Unusual AJAX requests to cryout-serious-slider endpoints from low-privilege accounts
• Slider functionality becoming unavailable or degraded without administrative changes

Detection Strategies

• Enable WordPress audit logging to track all plugin-related actions and user role associations
• Monitor for unexpected POST requests to slider-related endpoints from non-administrator users
• Implement Web Application Firewall (WAF) rules to detect access control bypass attempts
• Review user activity logs for subscribers or contributors making administrative plugin changes

Monitoring Recommendations

• Configure alerts for any slider modifications performed by users without editor or administrator roles
• Deploy endpoint detection to identify WordPress plugin exploitation patterns
• Regularly audit WordPress user accounts to ensure principle of least privilege
• Monitor for bulk or automated requests to plugin AJAX handlers that may indicate exploitation

How to Mitigate CVE-2026-25399

Immediate Actions Required

• Update the Serious Slider plugin to a version newer than 1.2.7 when a patch becomes available
• Audit existing WordPress user accounts and remove unnecessary access privileges
• Consider temporarily deactivating the Serious Slider plugin if a patch is not yet available
• Review and restrict subscriber and contributor account creation on affected sites

Patch Information

At the time of publication, organizations should monitor for an updated version of the Serious Slider plugin from CryoutCreations that addresses this authorization bypass vulnerability. Check the Patchstack Vulnerability Advisory for the latest patch status and remediation guidance.

Workarounds

• Restrict WordPress user registration to prevent unauthorized account creation
• Implement additional access control at the web server or WAF level for plugin endpoints
• Remove or disable the Serious Slider plugin until an official patch is released
• Limit network access to the WordPress admin dashboard to trusted IP addresses only

# WordPress configuration to restrict user registration
# Add to wp-config.php to prevent open registration exploitation
define('WP_ALLOW_MULTISITE', false);

# Consider adding to .htaccess to restrict plugin admin access by IP
# <Files "admin-ajax.php">
#   Order Deny,Allow
#   Deny from all
#   Allow from YOUR_TRUSTED_IP
# </Files>