CVE-2025-62880 identifies a Cross-Site Request Forgery (CSRF) vulnerability in the Custom 404 Pro plugin developed by Kunal Nagar, affecting versions up to 3.12.0. CSRF vulnerabilities occur when a web application does not adequately verify that requests made to it originate from legitimate users, allowing attackers to trick authenticated users into submitting forged requests. In this case, the plugin lacks proper CSRF protections, such as anti-CSRF tokens or origin checks, enabling attackers to craft malicious links or web pages that, when visited by an authenticated user, cause unintended actions to be performed on the vulnerable site. The CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N) indicates that the attack can be performed remotely over the network with low attack complexity, requires no privileges, but does require user interaction. The vulnerability impacts the integrity of the affected system by allowing unauthorized changes but does not compromise confidentiality or availability. No patches or fixes are currently linked, and no known exploits have been reported in the wild as of the publication date. The vulnerability was reserved in October 2025 and published in December 2025, indicating recent discovery and disclosure. The affected product is commonly used in WordPress environments to customize 404 error pages, which means the vulnerability primarily affects websites using this plugin.

For European organizations, the impact of this CSRF vulnerability can range from minor to moderate depending on how the Custom 404 Pro plugin is used within their web infrastructure. Since the vulnerability allows unauthorized integrity modifications without affecting confidentiality or availability, attackers could potentially alter plugin settings or trigger unintended actions that degrade user experience or site functionality. This could lead to reputational damage, especially for organizations relying on their web presence for customer engagement or e-commerce. Additionally, if the plugin is part of a larger chain of vulnerabilities or misconfigurations, it could be leveraged as a stepping stone for more severe attacks. The requirement for user interaction limits mass exploitation but targeted phishing or social engineering campaigns could increase risk. European organizations with strict data protection regulations (e.g., GDPR) must also consider compliance implications if unauthorized changes lead to data exposure or service disruptions.

To mitigate this vulnerability, organizations should first monitor for official patches or updates from the plugin vendor and apply them promptly once available. In the absence of immediate patches, web administrators can implement several practical measures: 1) Employ Web Application Firewalls (WAFs) with rules designed to detect and block CSRF attack patterns targeting the plugin’s endpoints. 2) Enforce strict Content Security Policies (CSP) to reduce the risk of malicious script execution. 3) Review and harden user session management to limit the impact of forged requests, including shortening session lifetimes and requiring re-authentication for sensitive actions. 4) Implement custom CSRF tokens or nonce validation in the plugin’s code if feasible, or disable the plugin temporarily if it is not critical. 5) Educate users and administrators about phishing risks and the importance of not clicking suspicious links while authenticated. 6) Conduct regular security audits and penetration testing focusing on web application vulnerabilities, including CSRF. These steps help reduce the attack surface and protect the integrity of affected systems until a formal patch is released.