CVE-2025-64821 is a stored Cross-Site Scripting (XSS) vulnerability identified in Adobe Experience Manager (AEM) versions 6.5.23 and earlier. Stored XSS occurs when an attacker is able to inject malicious scripts into persistent storage, such as form fields, which are then served to other users. In this case, a low privileged attacker can submit malicious JavaScript code into vulnerable form fields within AEM-managed websites. When other users browse pages containing these fields, the injected script executes in their browsers within the context of the vulnerable site. This can lead to session hijacking, theft of sensitive information, or unauthorized actions performed on behalf of the victim user. The vulnerability requires the attacker to have at least low privileges to submit data and requires user interaction (visiting the affected page). The CVSS 3.1 base score is 5.4, reflecting network attack vector, low attack complexity, low privileges required, and user interaction needed. The impact affects confidentiality and integrity but not availability. No public exploits have been reported yet, and no patches are linked in the provided data, indicating the need for vigilance and proactive mitigation. Adobe Experience Manager is widely used by enterprises and public sector organizations for content management, making this vulnerability relevant for organizations relying on AEM for web presence and digital services.

For European organizations, this vulnerability poses a risk of client-side attacks that can compromise user sessions, leak sensitive data, or enable unauthorized actions on web portals managed by Adobe Experience Manager. Organizations in sectors such as government, finance, healthcare, and media that rely on AEM for public-facing or internal web applications could face reputational damage, regulatory penalties under GDPR if personal data is exposed, and operational disruptions. The ability of a low privileged attacker to inject scripts increases the attack surface, especially in environments where user input is not strictly controlled. Although the vulnerability does not affect availability, the confidentiality and integrity risks can lead to significant indirect impacts, including loss of customer trust and potential lateral movement if session tokens or credentials are stolen. The absence of known exploits reduces immediate risk but should not lead to complacency, as stored XSS vulnerabilities are commonly targeted once disclosed.

European organizations should implement a multi-layered mitigation approach beyond generic advice: 1) Apply any available Adobe patches or updates promptly once released. 2) Implement strict input validation and sanitization on all form fields to prevent injection of malicious scripts. 3) Use context-aware output encoding (e.g., HTML entity encoding) when rendering user input to prevent script execution. 4) Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. 5) Limit the privileges required to submit data to vulnerable forms, and restrict access to trusted users where possible. 6) Monitor web application logs and user activity for anomalous inputs or behaviors indicative of exploitation attempts. 7) Conduct regular security assessments and penetration testing focused on XSS vulnerabilities in AEM deployments. 8) Educate developers and administrators on secure coding practices specific to AEM and XSS mitigation. 9) Consider web application firewalls (WAFs) with tailored rules to detect and block XSS payloads targeting AEM. 10) Review and harden AEM configurations to minimize exposure of vulnerable components.