CVE-2025-62149 identifies a Stored Cross-Site Scripting (XSS) vulnerability in the SaifuMak Add Custom Codes plugin, which is used to insert custom code snippets into web pages. The vulnerability stems from improper neutralization of input during web page generation, classified under CWE-79. Specifically, the plugin fails to adequately sanitize or encode user-supplied input before embedding it into web pages, allowing malicious scripts to be stored persistently and executed in the browsers of other users who view the affected pages. The vulnerability affects all versions of Add Custom Codes up to 4.80. Exploitation requires an attacker to have high privileges (PR:H) and involves user interaction (UI:R), such as tricking a user into visiting a maliciously crafted page. The CVSS v3.1 base score is 5.9, indicating a medium severity level. The vector indicates network attack vector (AV:N), low attack complexity (AC:L), and a scope change (S:C), meaning the vulnerability can affect resources beyond the initially vulnerable component. The impacts include limited confidentiality, integrity, and availability losses, such as theft of session cookies, unauthorized actions performed on behalf of users, or defacement of web content. No patches or known exploits are currently available, but the vulnerability is publicly disclosed and should be addressed promptly to prevent potential exploitation. The vulnerability is particularly relevant for web applications relying on the Add Custom Codes plugin to customize content dynamically, where malicious input can be injected and stored.

For European organizations, the impact of CVE-2025-62149 can be significant in environments where the SaifuMak Add Custom Codes plugin is deployed, especially in web-facing applications or content management systems. Successful exploitation could allow attackers to execute arbitrary JavaScript in the context of authenticated users, leading to session hijacking, credential theft, or unauthorized actions such as modifying content or changing configurations. This can undermine user trust, cause reputational damage, and potentially lead to data breaches if sensitive information is exposed. The scope change in the CVSS vector suggests that the vulnerability could affect multiple components or users beyond the initial point of compromise. Although the vulnerability requires high privileges to exploit, insider threats or compromised administrator accounts could be leveraged. The requirement for user interaction means phishing or social engineering may be used to trigger the attack. European organizations with strict data protection regulations like GDPR must consider the compliance implications of any data leakage resulting from such attacks. Additionally, sectors with high web presence such as e-commerce, government portals, and financial services are at higher risk of operational disruption and financial loss.

To mitigate CVE-2025-62149, European organizations should implement the following specific measures: 1) Immediately review and restrict administrative access to the SaifuMak Add Custom Codes plugin to trusted personnel only, minimizing the risk of malicious input insertion. 2) Apply strict input validation and sanitization on all user-supplied data before it is stored or rendered, using context-appropriate encoding (e.g., HTML entity encoding) to neutralize potentially malicious scripts. 3) Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of any injected code. 4) Monitor and audit plugin usage logs for unusual activities or unauthorized code additions. 5) If available, update to a patched version of the plugin once released; in the absence of patches, consider disabling or replacing the plugin temporarily. 6) Educate administrators and users about phishing risks and the importance of cautious interaction with suspicious links or content. 7) Conduct regular security assessments and penetration testing focusing on web application input handling and stored XSS vulnerabilities. 8) Implement multi-factor authentication (MFA) for administrative accounts to reduce the risk of account compromise. These targeted actions go beyond generic advice by focusing on the plugin’s administrative scope, input handling, and layered defenses.