CVE-2026-92826 in EWWW Image Optimizer Plugin
Summary
by MITRE • 10/03/2026
The EWWW Image Optimizer plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via REQUEST_URI Parameter Key in all versions up to, and including, 8.7.7 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link. Successful exploitation requires that the enable_help option is active, as the vulnerable HelpScout Beacon script block is only emitted when that setting is enabled.
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Analysis
by VulDB Data Team • 10/03/2026
The EWWW Image Optimizer plugin for WordPress contains a reflected cross-site scripting vulnerability affecting all versions up to and including 8.7.7. This security flaw stems from insufficient input sanitization and output escaping mechanisms within the application code, specifically targeting the REQUEST_URI parameter key. The nature of this vulnerability allows unauthenticated attackers to inject arbitrary web scripts into pages served by the vulnerable WordPress installation. For exploitation to succeed, an attacker must trick a victim user into performing a specific action, such as clicking on a maliciously crafted link that contains the injected script payload within its URI parameters.
The operational impact of this vulnerability is significant because it enables attackers to execute arbitrary JavaScript in the context of the affected website and the browser session of any user who visits the compromised page. This can lead to various adverse outcomes, including session hijacking, credential theft, defacement of the website content, or redirection to malicious sites that may distribute malware. The vulnerability is classified under CWE-79, which covers Improper Neutralization of Input During Web Page Generation commonly known as Cross-site Scripting. From a tactical perspective, this aligns with ATT&CK technique T1059.007, indicating the use of JavaScript for client-side code execution during an attack chain.
A critical condition for successful exploitation is that the enable_help option must be active within the plugin configuration. The vulnerable HelpScout Beacon script block is only emitted when this specific setting is enabled, meaning that users who have disabled this feature are not exposed to this particular vector of attack. This dependency highlights the importance of reviewing and minimizing the surface area of installed plugins by disabling unnecessary features. Administrators should ensure that all optional components are turned off unless strictly required for business operations.
To mitigate this vulnerability, immediate action is recommended for all users running EWWW Image Optimizer versions 8.7.7 or earlier. The primary remediation step is to upgrade the plugin to a version later than 8.7.7 where the input sanitization and output escaping issues have been addressed by the developers. In addition to updating, administrators should audit their WordPress installations for any other plugins that may contain similar vulnerabilities. Implementing a Web Application Firewall can also provide an additional layer of defense by filtering out malicious requests before they reach the application logic. Regular security audits and adherence to secure coding practices are essential for maintaining the integrity of web applications against such injection-based attacks.