CVE-2025-10138: 
WordPress vulnerability analysis and mitigation

The This-or-That plugin for WordPress contains a Stored Cross-Site Scripting vulnerability (CVE-2025-10138) discovered on October 21, 2025. The vulnerability affects all versions up to and including 1.0.4 of the plugin. This security issue stems from insufficient input sanitization and output escaping on user-supplied attributes in the plugin's 'thisorthat' shortcode (NVD).

The vulnerability is classified as a Stored Cross-Site Scripting (XSS) issue, identified as CWE-79 (Improper Neutralization of Input During Web Page Generation). The CVSS v3.1 base score is 6.4 (Medium), with the vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N. The vulnerability exists in the plugin's 'thisorthat' shortcode functionality where user-supplied attributes are not properly sanitized or escaped before being stored and displayed (Wordfence).

The vulnerability allows authenticated attackers with contributor-level access or higher to inject arbitrary web scripts into pages. These malicious scripts will execute whenever a user accesses the compromised page, potentially leading to unauthorized data access or manipulation of user interactions (NVD).