CVE-2025-67554 identifies a Stored Cross-Site Scripting (XSS) vulnerability in the Humanityco Cookie Notice & Compliance for GDPR / CCPA plugin, specifically in versions up to and including 2.5.8. The vulnerability stems from improper neutralization of user-supplied input during the generation of web pages, which allows malicious scripts to be stored and later executed in the context of users visiting the affected website. This type of vulnerability is particularly dangerous because the malicious payload persists on the server and can affect multiple users. The CVSS v3.1 score of 5.9 (medium severity) reflects that exploitation requires network access, low attack complexity, but high privileges (PR:H), and user interaction (UI:R). The scope is changed (S:C), indicating that successful exploitation can affect resources beyond the vulnerable component. The impact includes limited confidentiality, integrity, and availability losses, such as theft of session tokens, defacement, or denial of service. No public exploits are known at this time, but the vulnerability poses a risk especially to websites relying on this plugin for GDPR and CCPA compliance, which are widely used in Europe. The vulnerability was published on December 9, 2025, and no patches or mitigations are currently linked, emphasizing the need for proactive defensive measures.

For European organizations, this vulnerability poses a risk to the confidentiality and integrity of user data, particularly sensitive personal data protected under GDPR. Attackers exploiting this Stored XSS could hijack user sessions, perform actions on behalf of users, or inject malicious content, potentially leading to reputational damage and regulatory penalties. Since the plugin is designed to manage cookie consent, exploitation could undermine user trust and compliance efforts. The availability impact is limited but could include denial of service through script-based attacks. Given the high prevalence of GDPR compliance tools in Europe, organizations using this plugin or similar solutions are at risk. The requirement for high privileges to exploit somewhat limits the attack surface but does not eliminate risk, especially in environments with multiple administrators or compromised credentials.

1. Monitor for and apply security patches or updates from Humanityco as soon as they become available. 2. Restrict administrative access to the plugin to trusted personnel only, employing strong authentication mechanisms such as multi-factor authentication (MFA). 3. Implement strict input validation and sanitization on all user inputs, especially those that are stored and rendered in web pages. 4. Deploy Content Security Policies (CSP) to restrict the execution of unauthorized scripts and reduce the impact of XSS attacks. 5. Conduct regular security audits and penetration testing focusing on web application vulnerabilities. 6. Educate administrators and users about phishing and social engineering risks that could lead to privilege escalation. 7. Consider isolating or sandboxing the plugin’s output to minimize the scope of potential script execution. 8. Monitor web logs and user activity for unusual behavior that might indicate exploitation attempts.