CVE-2026-27244: Adobe Experience Manager XSS Vulnerability

CVE-2026-27244 Overview

Adobe Experience Manager versions 6.5.23 and earlier are affected by a stored Cross-Site Scripting (XSS) vulnerability that could be abused by a low-privileged attacker to inject malicious scripts into vulnerable form fields. Malicious JavaScript may be executed in a victim's browser when they browse to the page containing the vulnerable field.

Critical Impact

Stored XSS vulnerabilities allow attackers to persistently inject malicious scripts that execute in victim browsers, potentially enabling session hijacking, credential theft, and unauthorized actions on behalf of authenticated users.

Affected Products

• Adobe Experience Manager versions 6.5.23 and earlier
• Adobe Experience Manager 6.5 LTS (all service packs)
• Adobe Experience Manager AEM Cloud Service

Discovery Timeline

• 2026-03-11 - CVE-2026-27244 published to NVD
• 2026-03-11 - Last updated in NVD database

Technical Details for CVE-2026-27244

Vulnerability Analysis

This stored Cross-Site Scripting (XSS) vulnerability (CWE-79) affects Adobe Experience Manager's form field handling functionality. Unlike reflected XSS attacks that require a victim to click a malicious link, stored XSS persists the malicious payload within the application itself. When an attacker with low-level privileges submits crafted JavaScript code through a vulnerable form field, the malicious script is stored in the application's database or content repository. Subsequently, when any user navigates to a page rendering that vulnerable field, the malicious JavaScript executes within their browser context.

The attack requires user interaction—specifically, a victim must browse to the page containing the injected payload. Once triggered, the attacker's script executes with the full permissions of the victim's session, potentially compromising both confidentiality and integrity of data within the AEM environment.

Root Cause

The vulnerability stems from insufficient input validation and output encoding in Adobe Experience Manager's form field processing. When user-supplied data is stored in form fields without proper sanitization, and subsequently rendered to other users without adequate output encoding, the browser interprets the stored content as executable JavaScript rather than display data. This represents a failure to adhere to secure coding practices that separate data from code during both storage and rendering operations.

Attack Vector

The attack is network-based and requires the attacker to have low-level privileges within the AEM environment to access and submit data to vulnerable form fields. The exploitation flow involves:

1. An authenticated attacker with minimal privileges identifies form fields that accept and store user input
2. The attacker crafts a malicious JavaScript payload and submits it through the vulnerable form field
3. The payload is stored in the AEM content repository without proper sanitization
4. When other users (including administrators) browse to pages rendering the vulnerable field, the malicious script executes in their browser
5. The script operates within the victim's session context, enabling data exfiltration, session hijacking, or unauthorized actions

The changed scope indicator means that a successful exploit can affect resources beyond the vulnerable component, potentially compromising other security domains within the victim's browser environment.

Detection Methods for CVE-2026-27244

Indicators of Compromise

• Unusual JavaScript code patterns stored in AEM form fields or content nodes
• Unexpected outbound network requests from client browsers to unknown domains
• Suspicious content modifications in AEM repositories, particularly in user-editable form fields

Detection Strategies

• Implement Content Security Policy (CSP) headers to detect and block unauthorized script execution
• Monitor AEM audit logs for unusual content modifications by low-privileged users
• Deploy web application firewall (WAF) rules to detect XSS payload patterns in form submissions
• Conduct regular content scanning of AEM repositories for stored malicious scripts

Monitoring Recommendations

• Enable verbose logging for content authoring and form submission activities
• Configure alerts for JavaScript code patterns detected in stored content
• Monitor browser console errors and CSP violation reports from client-side
• Track user session anomalies that may indicate session hijacking attempts

How to Mitigate CVE-2026-27244

Immediate Actions Required

• Apply the latest Adobe Experience Manager security update immediately
• Review AEM form fields and content nodes for existing malicious payloads
• Implement Content Security Policy (CSP) headers to restrict script execution sources
• Conduct security audit of user-submitted content stored in the AEM repository

Patch Information

Adobe has released security patches addressing this vulnerability as documented in Adobe Security Advisory APSB26-24. Organizations running Adobe Experience Manager versions 6.5.23 and earlier should upgrade to the latest patched version. For AEM Cloud Service deployments, ensure automatic updates are enabled and verify the latest security fixes have been applied.

Workarounds

• Restrict access to form field editing capabilities to trusted users only
• Implement strict input validation on all user-supplied form data at the application level
• Deploy a Web Application Firewall (WAF) with XSS detection rules as a compensating control
• Enable and enforce Content Security Policy (CSP) headers with strict script-src directives

# Example CSP header configuration for Apache
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; object-src 'none';"