CVE-2026-84095 in wp-review-slider-pro Plugin
Summary
by MITRE • 09/26/2026
The wp-review-slider-pro WordPress plugin before 12.7.12 does not perform a capability check on one of its AJAX handlers, and the nonce protecting it is generated for every visitor, allowing any authenticated user, such as a subscriber, to store arbitrary review content which is later output without escaping on public pages, leading to Stored Cross-Site Scripting.
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Analysis
by VulDB Data Team • 09/26/2026
The vulnerability identified in wp-review-slider-pro versions prior to 12.7.12 represents a critical failure in access control and input validation within the plugin's AJAX infrastructure. The core issue stems from an insufficient capability check on one of the administrative AJAX handlers, which is intended for managing review data but lacks proper authorization verification. In WordPress development, it is standard practice to restrict such operations to users with elevated privileges, typically administrators or editors, using functions like current_user_can(). By omitting this check, the plugin inadvertently exposes a functionality that should be restricted to privileged accounts to any user who can authenticate to the site. This architectural flaw allows attackers with low-privilege roles, such as subscribers, to interact directly with backend logic intended for content management and configuration.
Compounding the access control failure is the improper handling of nonces, which are cryptographic tokens used in WordPress to prevent Cross-Site Request Forgery attacks. The plugin generates a nonce that is valid for every visitor rather than binding it specifically to the authenticated user's session or role. This design oversight means that an attacker can easily obtain a valid nonce by simply loading any page on the site where the script is enqueued, as these tokens are often embedded in HTML source code accessible via standard HTTP requests. With both a bypassed capability check and a reusable nonce, an authenticated subscriber gains full write access to the review storage mechanism without triggering security warnings or being denied service.
The operational impact of this vulnerability is severe due to its combination with stored cross-site scripting capabilities. Once the attacker successfully submits malicious content through the vulnerable AJAX endpoint, the data is saved into the WordPress database without adequate sanitization. Subsequently, when this arbitrary review content is rendered on public-facing pages, it is output directly without escaping special characters or encoding HTML entities. This lack of output validation allows embedded JavaScript payloads to execute in the context of any visitor viewing the affected page. The resulting stored cross-site scripting attack enables persistent compromise of end-users who visit these pages, facilitating session hijacking, credential theft, defacement, or redirection to malicious sites.
From a classification perspective, this vulnerability aligns with CWE-862, which denotes Missing Authorization, as the system fails to enforce proper access controls for critical functions. Furthermore, it falls under CWE-79, known as Improper Neutralization of Input During Web Page Generation, commonly referred to as Cross-site Scripting (XSS). The exploitation path leverages ATT&CK technique T1059, specifically command and script interpretation via browser-based execution, allowing the attacker to run arbitrary scripts within the victim's browser. This persistent nature distinguishes it from reflected XSS attacks, making remediation more complex as cleanup requires not only patching the code but also purging any malicious entries already stored in the database by previous attackers.
Mitigation strategies must focus on immediate access control hardening and input validation enforcement. The primary fix involves implementing strict capability checks within all AJAX handlers to ensure that only users with appropriate administrative or editorial privileges can invoke these functions. Additionally, nonce generation should be tightly bound to specific user sessions using wp_create_nonce with a unique action string tied to the current logged-in user's ID, ensuring that tokens cannot be reused across different contexts or by unauthorized parties. Developers must also enforce rigorous output escaping when rendering any data retrieved from the database onto public pages, utilizing functions like esc_html() or wp_kses_post() depending on the expected content type. Upgrading to version 12.7.12 or later resolves these issues as they include the necessary patches for authorization and sanitization logic.