CVE-2025-48258 is a vulnerability classified under CWE-79, indicating an improper neutralization of input during web page generation, commonly known as Cross-site Scripting (XSS). This specific vulnerability affects the jetmonsters Mega Menu Block plugin, versions up to and including 1.0.6. The nature of the vulnerability is a Stored XSS, meaning that malicious scripts injected by an attacker are permanently stored on the target server (e.g., in a database or content management system) and then served to users who access the affected pages. This type of XSS is particularly dangerous because it can affect multiple users without requiring the attacker to repeatedly inject the payload. The CVSS 3.1 base score is 6.5, which is categorized as medium severity. The vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L) indicates that the attack can be launched remotely over the network (AV:N) with low attack complexity (AC:L), but requires some level of privileges (PR:L) and user interaction (UI:R). The scope is changed (S:C), meaning the vulnerability affects resources beyond the initially vulnerable component. The impact on confidentiality, integrity, and availability is low to moderate (C:L/I:L/A:L). The vulnerability arises because the Mega Menu Block plugin does not properly sanitize or encode user-supplied input before embedding it into web pages, allowing attackers to inject malicious JavaScript code. When other users visit the compromised pages, the malicious script executes in their browsers, potentially leading to session hijacking, defacement, redirection to malicious sites, or other malicious activities. No known exploits are currently reported in the wild, and no patches or updates have been linked yet. The vulnerability was published on May 19, 2025, and has been enriched by CISA, indicating recognition by authoritative cybersecurity entities.

For European organizations using the jetmonsters Mega Menu Block plugin, this vulnerability poses a significant risk to web application security and user trust. Stored XSS can lead to unauthorized access to user sessions, theft of sensitive information such as authentication tokens, and manipulation of website content. This can result in reputational damage, regulatory non-compliance (especially under GDPR due to potential data breaches), and financial losses. Organizations in sectors with high web traffic or those handling sensitive user data (e.g., e-commerce, government portals, financial services) are particularly vulnerable. The requirement for some privilege level and user interaction somewhat limits the attack surface but does not eliminate risk, especially in environments where multiple users have content editing or administrative rights. The changed scope indicates that the vulnerability could affect other components or users beyond the immediate plugin, potentially amplifying the impact. Given the widespread use of WordPress and related plugins in Europe, the threat could affect a broad range of organizations if the plugin is deployed. The absence of known exploits in the wild provides a window for proactive mitigation before active exploitation occurs.

1. Immediate mitigation should include auditing all instances of the jetmonsters Mega Menu Block plugin to identify affected versions (up to 1.0.6). 2. Since no official patch links are available, organizations should monitor vendor communications and security advisories for updates or patches and apply them promptly once released. 3. Implement Web Application Firewalls (WAFs) with rules designed to detect and block common XSS payloads targeting the Mega Menu Block plugin. 4. Conduct a thorough review and sanitize all user-generated content inputs related to the menu block, applying strict input validation and output encoding to neutralize malicious scripts. 5. Limit privileges for users who can edit or manage menu content to reduce the risk of privilege abuse. 6. Educate users about the risks of interacting with suspicious links or content that could trigger XSS attacks. 7. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. 8. Regularly scan web applications for XSS vulnerabilities using automated tools and manual penetration testing. 9. Prepare incident response plans to quickly address any detected exploitation attempts.