CVE-2023-48538 is a stored Cross-Site Scripting (XSS) vulnerability identified in Adobe Experience Manager (AEM) versions 6.5.18 and earlier. This vulnerability arises from insufficient input sanitization in certain form fields within the AEM platform, allowing a low-privileged attacker to inject malicious JavaScript code that is persistently stored on the server. When a victim user accesses the affected page containing the maliciously crafted input, the injected script executes in their browser context. This can lead to unauthorized actions such as session hijacking, credential theft, or performing actions on behalf of the victim user. The vulnerability is classified under CWE-79, indicating improper neutralization of input during web page generation. The CVSS v3.1 base score is 5.4 (medium severity), reflecting that the attack vector is network-based (remote), requires low privileges, and user interaction is necessary to trigger the exploit. The scope is changed (S:C), meaning the vulnerability affects resources beyond the initially vulnerable component. Confidentiality and integrity impacts are low, while availability is not affected. No known exploits are currently reported in the wild, and no official patches or mitigation links are provided at this time. The vulnerability was published on December 15, 2023, and is recognized by CISA as enriched intelligence. Given the widespread use of Adobe Experience Manager in enterprise content management and digital experience delivery, this vulnerability poses a risk to organizations relying on AEM for web content management, especially if they allow user-generated input without additional filtering or validation.

For European organizations using Adobe Experience Manager, this vulnerability could lead to targeted attacks where malicious actors inject scripts that execute in the browsers of site administrators, content editors, or end users. The impact includes potential theft of session cookies, enabling account takeover, unauthorized actions within the AEM environment, or pivoting to further internal network compromise. Since AEM is often used by large enterprises, government agencies, and public sector websites in Europe, exploitation could result in reputational damage, data leakage, and disruption of digital services. The medium severity score indicates moderate risk, but the actual impact depends on the deployment context, user roles, and exposure of vulnerable forms. Organizations with public-facing AEM instances accepting user input are at higher risk. The requirement for user interaction (visiting a malicious or compromised page) means social engineering or phishing could be used to trigger the exploit. Confidentiality and integrity impacts, although rated low, are significant in environments handling sensitive or regulated data under GDPR and other European data protection laws. Therefore, even moderate vulnerabilities warrant prompt attention to avoid compliance issues and operational risks.

1. Immediate mitigation should include restricting access to vulnerable form fields to trusted users only and implementing strict input validation and sanitization on all user-supplied data before it is stored or rendered. 2. Employ Content Security Policy (CSP) headers to limit the execution of unauthorized scripts in browsers accessing AEM-managed content. 3. Monitor logs and user activity for unusual input patterns or script injections. 4. Educate users and administrators about the risks of clicking on suspicious links or visiting untrusted pages that could trigger stored XSS. 5. Since no official patch is currently available, consider deploying web application firewalls (WAF) with custom rules to detect and block common XSS payloads targeting AEM. 6. Plan and prioritize upgrading to the latest AEM version once Adobe releases a security update addressing this vulnerability. 7. Conduct regular security assessments and penetration testing focused on input handling and XSS vulnerabilities in AEM deployments. 8. Review and harden user privilege assignments to minimize the impact of compromised accounts.