CVE-2026-54870 in Weaver Xtreme Plugin
Summary
by MITRE • 10/13/2026
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in wpweaver Weaver Xtreme Theme Support weaverx-theme-support allows Stored XSS.This issue affects Weaver Xtreme Theme Support: from n/a through 7.0.1.
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Analysis
by VulDB Data Team • 10/13/2026
The identified vulnerability represents a classic instance of Improper Neutralization of Input During Web Page Generation, commonly known as Cross-Site Scripting or XSS. Specifically, this flaw manifests as a Stored XSS within the Weaver Xtreme Theme Support plugin for WordPress, affecting versions ranging from n/a through 7.0.1. Unlike reflected XSS attacks where malicious scripts are executed immediately via a crafted link, stored vulnerabilities persist on the target server. In this context, an attacker can inject malicious JavaScript code into input fields that are subsequently saved to the database without proper sanitization or validation. When other users or administrators view the affected pages, the browser retrieves and executes this embedded script in their session context, leading to a persistent compromise of user data and site integrity.
From a technical perspective, the root cause lies in the insufficient filtering of special characters that have meaning in HTML and JavaScript contexts before they are rendered by the web application. The plugin fails to encode or escape user-supplied input such as script tags, event handlers, or other executable code fragments. This lack of output encoding allows the browser to interpret these inputs not merely as data but as active commands. Because the payload is stored server-side, it does not require complex social engineering tactics like phishing links for every victim; instead, any user with access rights who loads a page containing the tainted content will trigger the execution of the malicious script automatically.
The operational impact of this vulnerability is severe due to its persistent nature and potential reach within an administrative or multi-user environment. An attacker can steal session cookies, which may allow them to hijack active sessions for administrators or other privileged users if secure cookie flags are not properly configured. Furthermore, the ability to execute arbitrary JavaScript enables actions such as defacing web pages, redirecting users to malicious sites, performing cross-site request forgery attacks against authenticated functions, and harvesting sensitive information entered into forms on the compromised site. In a WordPress ecosystem where plugins often have broad access capabilities, this can lead to full compromise of the underlying website infrastructure if administrative privileges are obtained through session hijacking or privilege escalation techniques facilitated by the script execution.
This vulnerability aligns with CWE-79, which defines Improper Neutralization of Input During Web Page Generation as a category for cross-site scripting flaws where input is not properly validated before being included in web pages. Additionally, from an offensive security perspective, this behavior maps to MITRE ATT&CK technique T1059.007, specifically JavaScript execution within the browser environment. The stored nature of the attack also correlates with persistence mechanisms that allow attackers to maintain access or influence over multiple users without repeated exploitation attempts for each victim.
Mitigation strategies must focus on both immediate remediation and long-term defensive coding practices. The most effective solution is to upgrade the Weaver Xtreme Theme Support plugin to version 7.0.2 or later, where the developers have presumably implemented proper input sanitization and output encoding mechanisms. For organizations unable to update immediately due to compatibility concerns, implementing a Web Application Firewall can provide an additional layer of defense by filtering out known malicious payloads before they reach the application logic. Developers should adhere to strict security standards such as OWASP Top 10 guidelines, ensuring that all user inputs are validated against expected formats and that outputs are encoded according to their context using libraries designed for this purpose. Regular code audits focusing on data flow from input sources to output sinks are essential to prevent similar vulnerabilities in future updates or custom implementations.