CVE-2025-64839 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-supplied input in certain form fields, allowing a low-privileged attacker to inject malicious JavaScript code that is persistently stored on the server. When legitimate users access the affected pages containing the injected scripts, the malicious code executes within their browsers under the context of the vulnerable AEM domain. This can lead to various attack scenarios including session hijacking, theft of sensitive information, or unauthorized actions performed on behalf of the victim. The vulnerability requires the attacker to have some level of access to submit data (low privilege) and relies on user interaction (visiting the compromised page) for exploitation. The CVSS v3.1 base score of 5.4 reflects a medium severity, with attack vector being network-based, low attack complexity, requiring privileges, and user interaction. The scope is changed, indicating that the vulnerability can affect resources beyond the initially vulnerable component. No public exploits have been reported yet, but the presence of this vulnerability in widely used enterprise content management software makes it a significant concern. Adobe has not yet released patches at the time of this report, so organizations must rely on interim mitigations. The vulnerability is categorized under CWE-79, which is a common and well-understood class of web application security flaws.

For European organizations, the impact of CVE-2025-64839 can be significant due to the widespread use of Adobe Experience Manager in government, financial, healthcare, and large enterprise sectors. Exploitation could lead to unauthorized disclosure of sensitive information, including session tokens and personal data, potentially violating GDPR requirements. Attackers could leverage the vulnerability to perform phishing or social engineering attacks by injecting malicious content into trusted websites, damaging organizational reputation and user trust. Although the vulnerability does not directly affect system availability, the integrity and confidentiality of user sessions and data are at risk. This could facilitate further attacks such as privilege escalation or lateral movement within the network. The medium severity score suggests that while the vulnerability is not critical, it still poses a tangible threat that could be exploited in targeted attacks against high-value European targets. Organizations relying heavily on AEM for public-facing websites or internal portals should consider this a priority issue.

1. Monitor Adobe’s official channels for the release of security patches addressing CVE-2025-64839 and apply them promptly once available. 2. Implement strict input validation and output encoding on all form fields within AEM to prevent injection of malicious scripts. 3. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. 4. Limit user privileges to the minimum necessary, especially for users who can submit data to vulnerable form fields. 5. Conduct regular security audits and penetration testing focused on web application vulnerabilities, including stored XSS. 6. Educate users and administrators about the risks of XSS and encourage cautious behavior when interacting with web content. 7. Use web application firewalls (WAFs) with rules designed to detect and block XSS payloads targeting AEM. 8. Review and harden AEM configurations to disable or restrict features that allow untrusted input to be stored and rendered. 9. Implement logging and monitoring to detect suspicious activities related to form submissions and script execution. These measures collectively reduce the risk of exploitation until official patches are deployed.