CVE-2024-26089: Adobe Experience Manager XSS Vulnerability

CVE-2024-26089 Overview

CVE-2024-26089 is a DOM-based Cross-Site Scripting (XSS) vulnerability affecting Adobe Experience Manager (AEM) versions 6.5.20 and earlier, including AEM Cloud Service. The flaw allows an attacker to execute arbitrary JavaScript code in the context of a victim's browser session. Exploitation requires user interaction, as the victim must visit a web page containing a maliciously crafted script. The vulnerability is tracked under CWE-79 (Improper Neutralization of Input During Web Page Generation).

Critical Impact
Successful exploitation enables attackers to execute arbitrary JavaScript in the victim's browser, potentially leading to session data theft, unauthorized actions, or content manipulation within the AEM application context.

Affected Products

Adobe Experience Manager versions 6.5.20 and earlier
Adobe Experience Manager Cloud Service
Deployments referenced by CPE cpe:2.3:a:adobe:experience_manager:*:*:*:*:aem_cloud_service:*:*:*

Discovery Timeline

2024-06-13 - CVE-2024-26089 published to the National Vulnerability Database (NVD)
2024-06-13 - Adobe publishes Security Advisory APSB24-28
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-26089

Vulnerability Analysis

The vulnerability is a DOM-based XSS issue in Adobe Experience Manager. DOM-based XSS occurs when client-side JavaScript reads attacker-controllable data from a Document Object Model (DOM) source and writes it to a sink that supports code execution without proper sanitization. Because the payload never reaches the server in some cases, traditional server-side input filtering does not stop the attack. The vulnerability allows arbitrary JavaScript execution scoped to the victim's authenticated AEM session, enabling access to cookies, session tokens, and page content the user can view.

Root Cause

The root cause is improper neutralization of user-supplied input during web page generation (CWE-79). Client-side scripts in AEM consume input from DOM sources such as location.hash, location.search, or document.referrer and pass it to dangerous sinks without contextual output encoding. Adobe has not published the specific vulnerable component in the public advisory.

Attack Vector

Exploitation is network-based and requires user interaction. An attacker crafts a URL or web page containing a malicious script fragment targeting a vulnerable AEM endpoint. When an authenticated AEM user visits the link, the malicious payload executes in the browser under the origin of the AEM application. Refer to the Adobe Security Advisory APSB24-28 for vendor-provided technical context.

// No verified public proof-of-concept is available for this CVE.
// Refer to Adobe Security Advisory APSB24-28 for vendor guidance.

Detection Methods for CVE-2024-26089

Indicators of Compromise

HTTP requests to AEM instances containing suspicious URL fragments, query parameters, or encoded <script> payloads targeting client-side handlers.
Browser console errors or Content Security Policy (CSP) violation reports originating from AEM-hosted pages.
Unusual outbound requests from authenticated AEM user sessions to attacker-controlled domains, indicating potential session or token exfiltration.

Detection Strategies

Inspect web server and proxy logs for requests to AEM URLs containing payload markers such as javascript:, onerror=, or URL-encoded angle brackets in query strings and fragments.
Deploy a strict Content Security Policy on AEM front-end applications and monitor report-uri telemetry for violation events.
Perform DOM-based XSS scanning against AEM author and publish instances using automated tools that trace tainted DOM sources to sinks.

Monitoring Recommendations

Enable and centralize AEM access logs, dispatcher logs, and WAF logs to identify anomalous request patterns targeting client-side entry points.
Alert on authenticated AEM sessions performing unexpected privileged operations shortly after visiting an external referrer.
Track AEM version inventory against Adobe's advisory list to identify hosts still running versions 6.5.20 or earlier.

How to Mitigate CVE-2024-26089

Immediate Actions Required

Upgrade Adobe Experience Manager to a fixed release identified in Adobe Security Advisory APSB24-28.
For AEM as a Cloud Service, confirm the tenant is running the latest release channel provided by Adobe.
Educate administrators and authors on the risk of clicking links to AEM URLs received from untrusted sources.

Patch Information

Adobe addressed CVE-2024-26089 in the security update described in APSB24-28. Administrators of on-premises AEM should apply the corresponding Service Pack that supersedes 6.5.20. AEM as a Cloud Service customers receive the fix through Adobe's managed release cadence.

Workarounds

Deploy a Web Application Firewall (WAF) rule set that blocks common XSS payload patterns in requests targeting AEM endpoints.
Enforce a restrictive Content Security Policy that disallows inline scripts and unapproved script sources to limit exploitation impact.
Restrict access to AEM author instances to trusted networks and require VPN or SSO with strong authentication.

bash

# Example Apache Dispatcher / mod_headers Content Security Policy for AEM front-end
Header always set Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'; frame-ancestors 'self'; report-uri /csp-report"
Header always set X-Content-Type-Options "nosniff"
Header always set X-Frame-Options "SAMEORIGIN"