CVE-2025-64557 is a stored Cross-Site Scripting (XSS) vulnerability identified in Adobe Experience Manager (AEM) versions 6.5.23 and earlier. The vulnerability arises from insufficient sanitization of user-supplied input in certain form fields, allowing a low-privileged attacker to inject malicious JavaScript code that is stored persistently on the server. When other users access the affected pages containing the injected scripts, the malicious code executes in their browsers within the security context of the vulnerable AEM site. This can lead to theft of session tokens, user impersonation, or unauthorized actions performed on behalf of the victim. The vulnerability has a CVSS 3.1 base score of 5.4, indicating medium severity, with an attack vector over the network, low attack complexity, requiring low privileges and user interaction, and impacting confidentiality and integrity but not availability. The scope is changed (S:C), meaning the vulnerability affects components beyond the initially vulnerable component. No public exploits have been reported yet, but the presence of stored XSS in a widely used enterprise content management system poses a significant risk, especially for organizations relying on AEM for web content delivery and customer engagement. The vulnerability was published on December 10, 2025, with the reservation date on November 5, 2025. No official patches are currently linked, suggesting organizations should monitor Adobe advisories closely.

For European organizations, this vulnerability can lead to unauthorized disclosure of sensitive information such as session cookies or personal data, enabling attackers to hijack user sessions or perform actions with the victim’s privileges. This can damage organizational reputation, lead to regulatory non-compliance (e.g., GDPR violations), and result in financial losses. Since AEM is often used for public-facing websites and intranet portals, the attack surface is broad, potentially affecting employees, partners, and customers. The medium severity score reflects that while the vulnerability does not directly cause system downtime, it undermines confidentiality and integrity, which are critical for trust and compliance. Attackers exploiting this vulnerability could target European organizations with high-value web assets, including government agencies, financial institutions, and large enterprises, potentially leading to data breaches or defacement. The requirement for user interaction and low privileges lowers the barrier for exploitation, increasing risk in environments with many users and diverse access levels.

1. Monitor Adobe’s official security advisories and apply patches promptly once released for AEM versions 6.5.23 and earlier. 2. Implement strict input validation and output encoding on all user-supplied data in AEM forms to prevent script injection. 3. Employ Content Security Policy (CSP) headers to restrict execution of unauthorized scripts in browsers. 4. Limit privileges of users who can submit content to reduce the risk of malicious input. 5. Conduct regular security audits and penetration testing focused on web application vulnerabilities, especially stored XSS. 6. Use web application firewalls (WAFs) with rules designed to detect and block XSS payloads targeting AEM. 7. Educate users about the risks of interacting with suspicious content and encourage reporting of anomalies. 8. Review and harden AEM configurations to minimize exposure of vulnerable components and unnecessary services. 9. Log and monitor web application activity for unusual patterns that may indicate exploitation attempts.