CVE-2026-65533 in Smart SEO Tool Plugin
Summary
by MITRE • 07/23/2026
Contributor Cross Site Scripting (XSS) in Smart SEO Tool <= 4.1.2 versions.
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Analysis
by VulDB Data Team • 07/23/2026
The Smart SEO Tool plugin for WordPress presents a contributor-level cross site scripting vulnerability that allows authenticated users with limited privileges to execute malicious scripts within the context of other users' browsers. This vulnerability exists due to insufficient input validation and output sanitization mechanisms within the plugin's codebase, specifically affecting versions prior to 4.1.3. The flaw enables attackers who have gained contributor access to inject malicious payloads that persist in the application's database and execute when other users view affected pages or interact with the plugin functionality. According to CWE-79, this represents a classic cross site scripting weakness where the application fails to properly escape or filter user-supplied data before rendering it in web pages.
The technical implementation of this vulnerability occurs when contributor-level users submit content through the plugin's interface without proper sanitization of special characters and script tags. The malicious input is stored in the database and subsequently rendered back to other users without adequate HTML escaping or context-appropriate encoding. This creates a persistent XSS vector that can be exploited to steal session cookies, perform unauthorized actions on behalf of victims, or redirect them to malicious sites. The vulnerability affects the plugin's handling of user-generated content, meta descriptions, and other editable fields where input validation is insufficient.
The operational impact of this contributor-level XSS vulnerability extends beyond simple data theft or defacement. An attacker with contributor privileges can leverage this weakness to escalate their access within the WordPress environment, potentially leading to full administrator compromise if the victim is a privileged user. The persistent nature of stored XSS means that malicious scripts will execute whenever affected pages are loaded, providing attackers with ongoing access to target systems. This vulnerability also violates security principles outlined in the OWASP Top Ten 2021, specifically addressing the risk of insufficient logging and monitoring of user activities.
Mitigation strategies should focus on immediate plugin updates to version 4.1.3 or later where the XSS vulnerability has been patched. Administrators should implement role-based access controls to limit contributor privileges and ensure that only trusted users have access to potentially dangerous areas of the application. Input validation and output sanitization mechanisms must be strengthened through proper HTML escaping, context-aware encoding, and regular security audits of plugin code. The ATT&CK framework categorizes this vulnerability under T1548.003 for bypassing user account controls and T1059.001 for command and scripting interpreter execution. Additionally, implementing Content Security Policy headers can provide an additional layer of protection against XSS attacks by restricting script execution sources and preventing unauthorized code injection attempts.