CVE-2025-48096 identifies a missing authorization vulnerability in the FRESHFACE Custom CSS plugin, specifically within its custom-css-editor component. This vulnerability arises from incorrectly configured access control security levels, allowing unauthenticated attackers to access and modify CSS configurations without proper permissions. The affected versions include all versions up to and including 1.4.0, with no specific lower bound version identified. The vulnerability is exploitable remotely over the network without requiring any privileges or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). The impact primarily affects confidentiality and integrity, as unauthorized users can read or alter CSS files, potentially leading to UI manipulation, information leakage, or indirect attacks such as phishing or session hijacking through UI spoofing. Availability is not impacted. Although no known exploits have been reported in the wild, the vulnerability's nature makes it a candidate for exploitation in targeted attacks. The lack of patches at the time of publication necessitates immediate attention from users of the affected plugin. The vulnerability was reserved in May 2025 and published in October 2025, reflecting recent discovery and disclosure. The root cause is the absence of proper authorization checks in the custom-css-editor, which should enforce strict access control to prevent unauthorized modifications.

For European organizations, this vulnerability poses a risk to the confidentiality and integrity of web applications using the FRESHFACE Custom CSS plugin. Unauthorized modification of CSS can lead to UI defacement, misleading users, or exposing sensitive layout information that could facilitate further attacks. While the direct impact on availability is minimal, the reputational damage and potential for indirect attacks such as phishing or session hijacking are significant concerns. Organizations relying on this plugin for website customization may face compliance issues if unauthorized changes lead to data exposure. The ease of exploitation without authentication increases the threat level, especially for public-facing web services. This vulnerability could be leveraged by attackers to undermine user trust or conduct social engineering attacks, impacting sectors like e-commerce, government portals, and online services prevalent in Europe. The absence of known exploits currently provides a window for proactive mitigation but also indicates the need for vigilance.

To mitigate CVE-2025-48096, European organizations should: 1) Immediately restrict network access to the custom-css-editor interface using web application firewalls (WAFs) or IP whitelisting to limit exposure. 2) Monitor and audit CSS configuration changes for unauthorized modifications using file integrity monitoring tools. 3) Implement strict role-based access controls (RBAC) within the application environment to ensure only authorized personnel can access CSS editing features. 4) Apply patches or updates from FRESHFACE as soon as they become available; in the absence of official patches, consider disabling the custom-css-editor functionality temporarily. 5) Conduct security reviews of all web-facing components that integrate with the Custom CSS plugin to identify and remediate potential attack vectors. 6) Educate web administrators about the risks of unauthorized CSS changes and establish incident response procedures for suspected exploitation. 7) Employ Content Security Policy (CSP) headers to mitigate the impact of malicious CSS injections. These steps go beyond generic advice by focusing on access restriction, monitoring, and layered defense tailored to the plugin's specific vulnerability.