CVE-2026-115951 in Lazy Load for Videos Plugin
Summary
by MITRE • 10/26/2026
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Kevin Weber Lazy Load for Videos lazy-load-for-videos allows Stored XSS.This issue affects Lazy Load for Videos: from n/a through 2.18.11.
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Analysis
by VulDB Data Team • 10/26/2026
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 is classified under the CWE-79 standard within the Common Weakness Enumeration framework, which details weaknesses related to the injection of client-side scripts into web pages viewed by other users. In the context of the Lazy Load for Videos plugin developed by Kevin Weber, the issue manifests as a Stored Cross-Site Scripting attack vector. Unlike reflected XSS where malicious payloads are delivered via URLs or form submissions that require immediate user interaction with a crafted link, stored XSS involves the persistence of the malicious script within the application's data store. This means an attacker can inject harmful JavaScript code through input fields managed by the plugin, such as video metadata, titles, descriptions, or configuration settings, and have it saved on the server side for subsequent retrieval and execution.
The technical root cause lies in the insufficient validation and sanitization of user-supplied input before it is rendered back into the browser environment without proper encoding. When a victim with sufficient privileges to trigger the rendering of this data accesses the affected page or functionality, the web application serves the stored payload directly to their browser. The browser interprets the injected script as legitimate code belonging to the site's domain. This bypasses same-origin policy protections because the malicious content originates from the trusted server itself. The vulnerability affects versions of Lazy Load for Videos ranging from no specific lower bound through version 2.18.11, indicating a long-standing exposure in these releases where input handling mechanisms failed to implement robust output encoding strategies such as HTML entity encoding or context-aware escaping.
From an operational impact perspective, the consequences of this stored XSS vulnerability are severe and multifaceted. An attacker who successfully exploits this flaw can execute arbitrary JavaScript code within the security context of the vulnerable website. This capability allows for session hijacking, where the attacker steals authentication cookies or tokens to impersonate legitimate users, including administrators. It also enables keylogging capabilities to capture sensitive credentials entered on the site, defacement of web pages by altering displayed content, and redirection of users to malicious phishing sites designed to steal further information. Furthermore, because the payload is stored, a single successful injection can compromise every user who views the affected page, leading to widespread impact without requiring targeted social engineering for each victim beyond initial access to an input field that triggers storage.
In terms of threat modeling and adversary behavior, this vulnerability aligns with techniques documented in the MITRE ATT&CK framework, particularly T1059.007 which covers JavaScript execution on client-side browsers. The stored nature of the attack facilitates persistent access and broad dissemination of malicious payloads, making it a high-severity issue for web application security assessments. Attackers often leverage such vulnerabilities as part of larger campaigns to establish footholds in corporate networks or to conduct large-scale credential harvesting operations against user bases that trust the compromised platform.
Mitigation strategies must focus on both immediate remediation and long-term secure coding practices. The primary technical fix involves implementing strict input validation and output encoding for all data handled by the Lazy Load for Videos plugin. Developers should ensure that any user-controlled data rendered in HTML contexts is properly encoded to prevent browser interpretation as executable code. Utilizing Content Security Policy headers can also provide an additional layer of defense by restricting the sources from which scripts can be loaded, thereby mitigating the impact even if injection occurs. For end-users and site administrators, immediate action should include updating the plugin to a patched version that addresses this input neutralization flaw. If an update is not immediately available, temporary workarounds such as disabling user-contributed content features or implementing server-side filtering rules can reduce exposure until the software vendor releases a corrected release. Regular security audits and code reviews focusing on data flow from inputs to outputs are essential to prevent similar vulnerabilities in future development cycles.