CVE-2026-1910 in UpMenu Plugin
Summary
by MITRE • 02/14/2026
The UpMenu – Online ordering for restaurants plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'lang' attribute of the 'upmenu-menu' shortcode in all versions up to, and including, 3.1. This is due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
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Analysis
by VulDB Data Team • 02/19/2026
The CVE-2026-1910 vulnerability affects the UpMenu – Online ordering for restaurants WordPress plugin, specifically targeting versions up to and including 3.1. This security flaw represents a critical stored cross-site scripting vulnerability that exploits the 'lang' attribute within the 'upmenu-menu' shortcode implementation. The vulnerability exists due to inadequate input sanitization and output escaping mechanisms that fail to properly validate or sanitize user-supplied data before processing. Attackers can leverage this weakness to inject malicious scripts that persist within the plugin's functionality and execute whenever affected pages are accessed by users.
The technical exploitation of this vulnerability requires an attacker to possess contributor-level access or higher within the WordPress environment, which represents a significant operational risk since contributor accounts often have broad permissions to modify content and settings. The stored nature of this XSS vulnerability means that malicious scripts are permanently embedded within the plugin's shortcode processing, making the attack persistent and potentially affecting multiple users who access pages containing the compromised shortcode. This vulnerability directly maps to CWE-79 which defines Cross-Site Scripting as a weakness where untrusted data is used without proper validation or escaping to construct executable web pages.
The operational impact of this vulnerability extends beyond simple script injection, as it enables attackers to potentially escalate privileges, steal user sessions, perform unauthorized actions on behalf of victims, or redirect users to malicious websites. The attacker can craft payloads that exploit the 'lang' attribute to inject JavaScript code that could harvest cookies, redirect traffic, or even execute more sophisticated attacks such as credential theft. This vulnerability affects the integrity of the WordPress site and can compromise the security of all users who access pages utilizing the affected shortcode, creating a persistent threat vector that remains active until the vulnerability is patched.
Mitigation strategies for CVE-2026-1910 should prioritize immediate patching of the UpMenu plugin to version 3.2 or later, which contains the necessary security fixes. Administrators should also implement additional security measures including role-based access control restrictions, regular security audits of plugin installations, and monitoring for unauthorized modifications to shortcode attributes. The principle of least privilege should be enforced by limiting contributor access to only essential functionality and regularly reviewing user permissions. Security monitoring tools should be deployed to detect suspicious shortcode usage patterns and potential injection attempts. Additionally, implementing content security policies and regular security assessments of third-party plugins can help prevent similar vulnerabilities from being exploited in the future, aligning with ATT&CK technique T1059.007 for command and scripting interpreter and T1547.001 for registry run keys.