CVE-2025-49322 is a medium severity vulnerability classified under CWE-79, which corresponds to Improper Neutralization of Input During Web Page Generation, commonly known as Cross-site Scripting (XSS). This vulnerability affects the WordPress plugin '404 Page by SeedProd,' a tool used to create custom 404 error pages. The flaw allows for Stored XSS attacks, meaning that malicious scripts can be permanently stored on the target server and executed when a user accesses the affected 404 page. The vulnerability arises because user input is not properly sanitized or neutralized before being embedded into the web page, allowing attackers to inject arbitrary JavaScript code. The CVSS 3.1 base score is 5.9, indicating a medium severity level. The vector string (CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L) shows that the attack can be launched remotely over the network (AV:N) with low attack complexity (AC:L), but requires high privileges (PR:H) and user interaction (UI:R). The scope is changed (S:C), meaning the vulnerability affects resources beyond the initially vulnerable component. The impact affects confidentiality, integrity, and availability to a limited extent (C:L/I:L/A:L). No known exploits are currently reported in the wild, and no patches or fixed versions have been published yet. The affected versions are not specified, which may indicate the vulnerability affects all current versions or that version details are pending. Stored XSS vulnerabilities can lead to session hijacking, defacement, redirection to malicious sites, or execution of arbitrary actions on behalf of authenticated users, especially dangerous in administrative contexts.

For European organizations using the '404 Page by SeedProd' plugin, this vulnerability poses a significant risk, especially for websites with authenticated users or administrators who might visit the compromised 404 pages. Exploitation could lead to theft of session cookies, unauthorized actions performed with elevated privileges, or distribution of malware to site visitors. Given the scope change in the CVSS vector, the vulnerability might allow attackers to affect other components or users beyond the initially targeted page. This could result in data leakage, reputational damage, and potential regulatory non-compliance under GDPR if personal data is exposed or manipulated. Organizations relying on WordPress for customer-facing or internal portals should be particularly cautious, as attackers might leverage this vulnerability to escalate privileges or pivot to other parts of the network. The requirement for high privileges to exploit somewhat limits the attack surface but does not eliminate risk, especially if administrative accounts are compromised or if attackers can social engineer users into triggering the malicious payload.

1. Immediate mitigation should include restricting administrative access to the WordPress backend and enforcing strong authentication mechanisms such as multi-factor authentication (MFA) to reduce the risk of privilege escalation. 2. Monitor and audit user inputs and logs for suspicious activities related to 404 page requests or unusual script injections. 3. Implement Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts on the website. 4. Until an official patch is released, consider disabling or uninstalling the '404 Page by SeedProd' plugin if feasible, or replace it with alternative plugins that have been verified as secure. 5. Educate users and administrators about the risks of clicking on suspicious links or interacting with unexpected 404 pages. 6. Regularly update WordPress core and all plugins to their latest versions once patches addressing this vulnerability become available. 7. Employ web application firewalls (WAF) with rules designed to detect and block XSS payloads targeting the 404 page functionality. 8. Conduct penetration testing focused on stored XSS vectors in custom error pages to identify and remediate similar issues proactively.