CVE-2026-102798 in ThemeREX Addons Plugin
Summary
by MITRE • 10/02/2026
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in ThemeREX Group ThemeREX Addons trx_addons allows Stored XSS.This issue affects ThemeREX Addons: from n/a through 2.46.0.
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Analysis
by VulDB Data Team • 10/02/2026
The identified security flaw represents a classic instance of Improper Neutralization of Input During Web Page Generation, commonly known as Cross-Site Scripting or XSS. Specifically, this vulnerability manifests within the ThemeREX Addons plugin for WordPress, affecting versions ranging from its initial release up through version 2.46.0. The core technical deficiency lies in the application's failure to adequately sanitize user-supplied input before it is processed and subsequently rendered by the web browser. This lack of proper validation allows an attacker to inject malicious scripts into pages that are viewed by other users, thereby bypassing standard security controls such as the same-origin policy which normally isolates websites from each other to prevent malicious scripting.
In a stored XSS scenario, also referred to as persistent cross-site scripting, the injected script is not executed immediately but is instead saved on the target server, typically within a database or content management system. When ThemeREX Addons processes input fields that are susceptible to this flaw without applying appropriate encoding or escaping mechanisms, it stores these malicious payloads directly into its data storage. Consequently, every time a legitimate user loads a webpage containing this compromised data, their browser executes the embedded script in the context of the vulnerable website. This persistence distinguishes stored XSS from reflected variants, as the attack vector remains active until the malicious content is manually removed or expires, significantly increasing the potential blast radius and duration of the compromise.
The operational impact of such a vulnerability is severe and multifaceted. Attackers can leverage this flaw to steal sensitive session cookies, which may lead to account takeover if multi-factor authentication is not strictly enforced. Furthermore, the malicious scripts can perform actions on behalf of the victim user, potentially altering site content, defacing web pages, or redirecting users to phishing sites designed to harvest credentials. In more sophisticated attacks, the script could be used to deploy further malware onto the visitor's machine by exploiting browser vulnerabilities or tricking the user into downloading malicious files under the guise of legitimate website functionality. This undermines the integrity and confidentiality of both the end-user data and the administrative controls of the WordPress site itself.
From a classification perspective, this vulnerability aligns with CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'). It also maps to specific tactics within the MITRE ATT&CK framework, particularly T1059.007 which covers JavaScript execution and potentially T1204.002 for Malicious File Download if file-based payloads are utilized. The failure occurs during the input validation phase, indicating a gap in the defense-in-depth strategy where trusted data is assumed to be safe without rigorous verification against expected formats or character sets.
To mitigate this risk, immediate action must be taken by site administrators and developers. The primary remediation step involves upgrading ThemeREX Addons to a version newer than 2.46.0, as the vendor has presumably addressed these input handling deficiencies in subsequent releases. Until an update is applied or if no patch exists for specific legacy environments, defensive coding practices should be implemented at the application layer. This includes enforcing strict allow-list validation on all user inputs and applying context-sensitive output encoding to ensure that special characters are converted into their HTML entity equivalents before rendering. Additionally, implementing a Content Security Policy header can help mitigate the impact of any successfully injected scripts by restricting the sources from which executable content is allowed to load, thereby reducing the effectiveness of client-side attacks even if they bypass input validation controls.