CVE-2025-64820 is a stored Cross-Site Scripting (XSS) vulnerability identified in Adobe Experience Manager (AEM) versions 6.5.23 and earlier. Stored XSS occurs when malicious input is permanently stored on the target server, such as within form fields, and later rendered in users' browsers without proper sanitization or encoding. In this case, a low-privileged attacker can inject arbitrary JavaScript code into vulnerable form fields within AEM. When legitimate users access pages containing these fields, the malicious script executes in their browsers, potentially allowing the attacker to steal session cookies, perform actions on behalf of the user, or redirect users to malicious sites. The vulnerability has a CVSS 3.1 base score of 5.4, indicating medium severity, with an attack vector of network, low attack complexity, requiring privileges, and user interaction. The scope is changed, meaning the vulnerability affects components beyond the initially vulnerable part. No public exploits are known yet, but the risk remains significant due to AEM's widespread use in enterprise content management. The vulnerability impacts confidentiality and integrity but not availability. Adobe has not yet released a patch, so organizations must rely on interim mitigations.

For European organizations, the impact of this vulnerability can be substantial, especially for those relying on Adobe Experience Manager to deliver web content and digital experiences. Successful exploitation could lead to unauthorized access to sensitive user data, session hijacking, and potential defacement or redirection of websites. This undermines user trust and can lead to regulatory repercussions under GDPR if personal data is compromised. The medium severity score reflects moderate risk, but the widespread adoption of AEM in sectors such as finance, government, and e-commerce across Europe amplifies the potential damage. Attackers exploiting this vulnerability could target employees or customers, leading to credential theft or further network infiltration. Additionally, the stored nature of the XSS means the malicious payload persists, increasing exposure duration. The requirement for user interaction limits automated exploitation but does not eliminate risk, especially in phishing or social engineering scenarios.

1. Monitor Adobe’s official channels for patches and apply them promptly once released. 2. Until a patch is available, implement strict input validation and output encoding on all form fields within AEM to prevent malicious script injection. 3. Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. 4. Limit user privileges on AEM to reduce the ability of low-privileged users to inject malicious content. 5. Conduct regular security audits and penetration testing focusing on web application vulnerabilities, including XSS. 6. Educate users about phishing risks and suspicious links to reduce the likelihood of triggering malicious scripts. 7. Use web application firewalls (WAFs) with rules designed to detect and block XSS payloads targeting AEM. 8. Review and sanitize any existing stored data in vulnerable form fields to remove malicious scripts. 9. Implement multi-factor authentication to reduce the impact of session hijacking if exploitation occurs.