CVE-2025-64857 is a stored Cross-Site Scripting (XSS) vulnerability identified in Adobe Experience Manager (AEM) versions 6.5.23 and earlier. This vulnerability arises from insufficient sanitization of user input in certain form fields, allowing a low-privileged attacker to inject malicious JavaScript code that is persistently stored on the server. When other users access the affected pages containing these fields, the malicious script executes in their browsers, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of the victim. The vulnerability has a CVSS v3.1 base score of 5.4, indicating a medium severity level. The attack vector is network-based (AV:N), requiring low attack complexity (AC:L), with low privileges (PR:L) but requiring user interaction (UI:R). The scope is changed (S:C), meaning the vulnerability can affect resources beyond the vulnerable component. The impact affects confidentiality and integrity partially (C:L/I:L) but does not affect availability (A:N). No patches or known exploits are currently available, but the vulnerability is published and should be addressed promptly. Stored XSS vulnerabilities are particularly dangerous in web content management systems like AEM, as they can affect a wide user base and facilitate further attacks such as phishing or malware distribution.

For European organizations, the impact of this vulnerability can be significant, especially for those relying on Adobe Experience Manager to deliver digital content and services. Exploitation could lead to unauthorized access to user sessions, theft of sensitive information, and manipulation of web content integrity. This can damage organizational reputation, lead to regulatory non-compliance (e.g., GDPR breaches due to data leakage), and cause operational disruptions if attackers leverage the vulnerability for further attacks. Public-facing AEM instances are particularly at risk, as attackers can target a broad audience. The medium severity score indicates moderate risk, but the potential for widespread impact in large enterprises or government portals makes this a critical consideration. Additionally, the requirement for user interaction means social engineering or phishing could be used to increase exploitation success. The absence of known exploits currently provides a window for proactive mitigation.

1. Implement strict input validation and sanitization on all form fields within Adobe Experience Manager to prevent injection of malicious scripts. 2. Deploy and enforce Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. 3. Regularly audit and monitor web application logs and user activity for signs of suspicious input or anomalous behavior. 4. Isolate and restrict privileges of users who can submit content to minimize the risk from low-privileged attackers. 5. Apply any available security updates or patches from Adobe promptly once released. 6. Educate users and administrators about the risks of XSS and the importance of cautious interaction with web content. 7. Consider implementing web application firewalls (WAF) with rules tailored to detect and block XSS payloads targeting AEM. 8. Conduct penetration testing focused on XSS vulnerabilities to identify and remediate any overlooked injection points. 9. Review and harden AEM configurations to minimize exposure of vulnerable components. 10. Prepare incident response plans to quickly address potential exploitation attempts.