CVE-2026-75711: Adobe Experience Manager XSS Vulnerability

CVE-2026-75711 Overview

Adobe Experience Manager (AEM) contains a DOM-based Cross-Site Scripting (XSS) vulnerability [CWE-79] that allows an attacker to execute arbitrary JavaScript in a victim's browser. Exploitation requires user interaction: the victim must visit a crafted webpage that manipulates the DOM environment. The vulnerability has a changed scope, meaning impact extends beyond the vulnerable component to other trust boundaries.

The flaw affects multiple AEM deployments, including AEM Cloud Service and AEM 6.5 LTS through Service Pack 2. Attackers who exploit this issue can hijack sessions, steal sensitive data rendered in the browser, or perform actions within the context of the authenticated user.

Critical Impact
Successful exploitation enables arbitrary JavaScript execution in an authenticated AEM user's browser, with a changed scope allowing impact across trust boundaries.

Affected Products

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

Discovery Timeline

2026-09-08 - CVE-2026-75711 published to the National Vulnerability Database (NVD)
2026-09-10 - Last updated in NVD database

Technical Details for CVE-2026-75711

Vulnerability Analysis

The vulnerability is a DOM-based Cross-Site Scripting (XSS) flaw within Adobe Experience Manager. Unlike reflected or stored XSS, DOM-based XSS occurs entirely on the client side. An attacker crafts input that a vulnerable client-side script writes into the DOM using an unsafe sink, such as innerHTML, document.write, or eval, without proper sanitization.

When an authenticated AEM user visits a malicious page or clicks a crafted link, JavaScript executes in the origin of the AEM application. The changed scope indicator (S:C) reflects that the executed script can reach resources beyond the vulnerable component, including cookies, tokens, or authenticated API surfaces available to the user's browser session.

The flaw requires low privileges and user interaction, limiting drive-by mass exploitation. However, in an AEM administrative context, a successful attack can lead to content tampering, credential theft, or lateral movement into the content management workflow.

Root Cause

The root cause is insufficient neutralization of input during web page generation on the client side [CWE-79]. A JavaScript component within AEM reads attacker-controllable data from a DOM source, such as location.hash, location.search, or postMessage data, and passes it to a dangerous sink without HTML or JavaScript context-aware escaping.

Attack Vector

Exploitation is remote and network-based. An attacker hosts or distributes a crafted URL or webpage that manipulates DOM properties the vulnerable AEM script consumes. When a victim with an active AEM session visits the page, the injected payload executes with the privileges of the victim's browser session against the AEM origin.

Refer to the Adobe Experience Manager Security Advisory (APSB26-98) for vendor-supplied technical details.

Detection Methods for CVE-2026-75711

Indicators of Compromise

Unusual outbound requests from browsers of AEM authors or administrators to unknown domains shortly after visiting third-party links.
Web server or CDN logs showing AEM URLs containing suspicious fragments, encoded <script> payloads, or event handler strings such as onerror=, onload=, or javascript:.
Unexpected session token exfiltration attempts or anomalous API calls originating from authenticated author sessions.

Detection Strategies

Deploy Content Security Policy (CSP) reporting to capture violations that indicate injected script execution against AEM origins.
Inspect browser telemetry and endpoint EDR data for JavaScript-driven navigation events, cookie access, or fetch calls initiated from AEM tabs.
Correlate AEM audit logs with web proxy logs to identify author accounts performing unusual actions after visiting external links.

Monitoring Recommendations

Monitor AEM author and admin accounts for anomalous content modifications, permission changes, or workflow submissions.
Alert on referrer patterns showing AEM sessions accessed from untrusted external domains.
Track CSP violation reports and web application firewall (WAF) alerts for XSS signatures targeting AEM URLs.

How to Mitigate CVE-2026-75711

Immediate Actions Required

Apply the security updates referenced in the Adobe Experience Manager Security Advisory (APSB26-98) to all affected AEM Cloud Service and AEM 6.5 LTS deployments.
Restrict AEM author instance access to trusted networks or VPN, reducing exposure to attacker-controlled links reaching privileged users.
Instruct AEM authors and administrators to avoid clicking untrusted links while authenticated to the platform.

Patch Information

Adobe has released fixes documented in security bulletin APSB26-98. Administrators running AEM as a Cloud Service should confirm their instance is on a patched release channel. On-premises customers running AEM 6.5 LTS (base, SP1, or SP2) must upgrade to the fixed Service Pack or hotfix identified in the advisory.

Workarounds

Enforce a strict Content Security Policy (CSP) on AEM origins to block inline script execution and restrict script sources.
Configure the AEM Dispatcher and upstream WAF to filter suspicious query parameters, fragments, and payloads targeting known DOM sinks.
Require re-authentication for sensitive administrative operations to limit the value of a hijacked session.

bash

# Configuration example: sample CSP header for AEM author instance
# Adjust script-src and connect-src to match your deployment
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"