CVE-2026-84820 in Unlimited Elements Plugin
Summary
by MITRE • 09/08/2026
Unauthenticated Cross Site Scripting (XSS) in Unlimited Elements For Elementor (Free Widgets, Addons, Templates) <= 2.0.17 versions.
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Analysis
by VulDB Data Team • 09/08/2026
The vulnerability identified as an unauthenticated cross-site scripting flaw within the Unlimited Elements for Elementor plugin affects all installations running version 2.0.17 and earlier. This security issue stems from insufficient input validation and sanitization mechanisms when processing user-supplied data, allowing attackers to inject malicious client-side scripts into web pages viewed by other users. As an unauthenticated vulnerability, it does not require any form of login or privilege escalation to exploit, significantly lowering the barrier for entry for threat actors who may lack legitimate access credentials to the WordPress dashboard.
From a technical perspective, the flaw typically resides in how the plugin handles parameters passed through HTTP requests, such as query strings or POST data, without adequately stripping out potentially dangerous HTML tags and JavaScript event handlers. When this unsanitized input is subsequently rendered back into the browser context of an administrator or another privileged user, the malicious script executes within the security context of the trusted website domain. This behavior aligns closely with CWE-79, which classifies improper neutralization of input during web page generation as a primary cause for cross-site scripting vulnerabilities. The lack of output encoding ensures that the browser interprets the injected content as executable code rather than plain text data.
The operational impact of this vulnerability is severe due to its unauthenticated nature and the typical privileges associated with WordPress administrators. An attacker can craft a malicious link or embed a script in a public-facing page, waiting for an administrator to view it. Once executed, the script can perform actions on behalf of the victim, such as stealing session cookies, hijacking administrative sessions, performing unauthorized state-changing requests like deleting posts or installing new plugins, and defacing the website content. This capability effectively allows full control over the compromised WordPress instance if the targeted user holds an administrator role, leading to potential data breaches, malware distribution, and significant reputational damage for the organization hosting the site.
This vulnerability maps directly to MITRE ATT&CK technique T1059.007, which covers JavaScript execution within web browsers as a method of initial access or persistence. By leveraging this flaw, attackers can establish persistent backdoors or exfiltrate sensitive information stored in local storage and cookies without triggering traditional authentication-based intrusion detection systems that rely on login attempts for alerting. The absence of required authentication makes it particularly dangerous in automated scanning campaigns where bots target known vulnerable plugins to compromise large numbers of sites simultaneously.
To mitigate this risk, site administrators must immediately update the Unlimited Elements plugin to version 2.0.18 or later, which includes patches addressing these input validation deficiencies. In addition to updating, implementing a Web Application Firewall can provide an additional layer of defense by filtering out malicious payloads before they reach the application logic. It is also advisable to enforce strict Content Security Policy headers that restrict script execution sources and disable inline scripts where possible, thereby reducing the impact even if similar vulnerabilities are discovered in future updates. Regular security audits and monitoring for unusual administrative activity can further aid in detecting exploitation attempts early.