CVE-2026-48261: Adobe Experience Manager XSS Vulnerability

CVE-2026-48261 Overview

CVE-2026-48261 is a DOM-based Cross-Site Scripting (XSS) vulnerability affecting Adobe Experience Manager (AEM). An attacker can manipulate the Document Object Model (DOM) environment to execute malicious JavaScript within the context of the victim's browser. Successful exploitation requires user interaction: the victim must visit a crafted webpage. The scope is changed, meaning the vulnerability can affect resources beyond the vulnerable component's security scope. The flaw is tracked under [CWE-79] (Improper Neutralization of Input During Web Page Generation).

Critical Impact
Successful exploitation allows attackers to execute arbitrary JavaScript in the victim's browser session, enabling session token theft, credential harvesting, or unauthorized actions against the AEM instance.

Affected Products

Adobe Experience Manager Cloud Service (AEM CS)
Adobe Experience Manager 6.5 LTS (base release)
Adobe Experience Manager 6.5 LTS Service Pack 1 and Service Pack 2

Discovery Timeline

2026-07-14 - CVE-2026-48261 published to the National Vulnerability Database
2026-07-17 - Last updated in NVD database

Technical Details for CVE-2026-48261

Vulnerability Analysis

CVE-2026-48261 is a client-side DOM-based XSS flaw in Adobe Experience Manager. Unlike stored or reflected XSS, DOM-based XSS executes entirely in the browser without the malicious payload necessarily touching the server response body. AEM JavaScript reads attacker-controllable data from a DOM source and writes it to a dangerous sink, allowing script execution.

Because the scope is changed, script execution in the AEM origin can pivot into adjacent security contexts, such as AEM Sites author sessions or integrated services. An authenticated low-privilege user or an unauthenticated victim tricked into visiting a crafted URL is sufficient for exploitation.

Root Cause

The root cause is improper neutralization of input during web page generation on the client side [CWE-79]. AEM client-side scripts pass untrusted values from sources such as document.location, document.URL, or window.name into sinks like innerHTML, document.write, or eval without adequate encoding or validation.

Attack Vector

The attacker crafts a URL containing malicious JavaScript in a fragment, query parameter, or other DOM-reachable input. The victim, who must have an active AEM session or be interacting with the AEM origin, clicks the link. The vulnerable client-side handler parses the input and injects it into a sink, executing the attacker's script under the AEM origin.

The vulnerability requires low attacker privileges and user interaction. Payloads typically leverage fragment identifiers because they are not sent to the server, evading server-side logging and web application firewall inspection.

See the Adobe Experience Manager Security Advisory APSB26-74 for vendor-provided technical details.

Detection Methods for CVE-2026-48261

Indicators of Compromise

Unusual URLs targeting AEM endpoints containing encoded JavaScript payloads in query strings or fragments, such as javascript:, <script>, or onerror= sequences.
Unexpected outbound requests from AEM author or publish origin to attacker-controlled domains following user visits to crafted links.
Anomalous session token usage, including reuse of AEM authentication cookies from unexpected IP addresses or user agents.

Detection Strategies

Inspect web server, reverse proxy, and CDN logs for AEM URLs containing script-like tokens in query parameters or fragments.
Deploy a strict Content Security Policy (CSP) in report-only mode to surface script-src violations that indicate exploitation attempts.
Correlate browser-side error telemetry and Real User Monitoring (RUM) data for unexpected script errors on AEM pages.

Monitoring Recommendations

Enable and forward AEM Dispatcher access logs to a centralized SIEM for URL pattern analysis.
Monitor for phishing campaigns and inbound emails carrying links to legitimate AEM domains with suspicious query strings.
Alert on authentication events immediately following redirects to external hosts referencing the AEM origin.

How to Mitigate CVE-2026-48261

Immediate Actions Required

Apply Adobe's security patches referenced in advisory APSB26-74 to all AEM Cloud Service and AEM 6.5 LTS deployments.
Enforce a strict Content Security Policy on AEM author and publish instances to restrict inline script execution.
Rotate AEM administrator and author session tokens after patching to invalidate any potentially compromised sessions.

Patch Information

Adobe released fixes documented in Adobe Security Bulletin APSB26-74. Customers on AEM Cloud Service receive updates through Adobe's managed release channel. AEM 6.5 LTS customers, including SP1 and SP2 deployments, must apply the corresponding service pack or hotfix identified in the advisory.

Workarounds

Restrict access to AEM author instances behind a VPN or IP allowlist until patches are deployed.
Configure the AEM Dispatcher to filter query parameters and fragments containing HTML or JavaScript metacharacters.
Educate content authors and administrators to avoid clicking untrusted links that reference AEM hostnames.

bash

# Example AEM Dispatcher filter to block suspicious script tokens in URLs
/0100 { /type "deny" /url '*<script*' }
/0101 { /type "deny" /url '*javascript:*' }
/0102 { /type "deny" /url '*onerror=*' }