CVE-2026-75677: Adobe Experience Manager XSS Vulnerability

CVE-2026-75677 Overview

Adobe Experience Manager (AEM) contains a DOM-based Cross-Site Scripting (XSS) vulnerability tracked as CVE-2026-75677. An attacker can manipulate the Document Object Model (DOM) environment to execute arbitrary JavaScript within the victim's browser session. Exploitation requires user interaction, specifically that a targeted user visits a crafted webpage. The vulnerability has a changed scope, meaning successful exploitation impacts resources beyond the vulnerable component's security authority. Adobe addressed the flaw in security advisory APSB26-98.

Critical Impact
Attackers with low-privileged access can inject client-side scripts that execute in a victim's authenticated AEM session, enabling content tampering, session context abuse, and cross-origin impact through the changed-scope condition.

Affected Products

Adobe Experience Manager Cloud Service (AEM as a Cloud Service)
Adobe Experience Manager 6.5 LTS (base release, SP1, SP2)
Adobe Experience Manager on-premise and AMS deployments

Discovery Timeline

2026-09-08 - CVE-2026-75677 published to the National Vulnerability Database
2026-09-10 - Last updated in NVD database

Technical Details for CVE-2026-75677

Vulnerability Analysis

CVE-2026-75677 is a DOM-based Cross-Site Scripting flaw classified under CWE-79: Improper Neutralization of Input During Web Page Generation. Unlike reflected or stored XSS, DOM-based XSS occurs entirely on the client side. Vulnerable JavaScript executed by the AEM front-end reads attacker-controlled input from a DOM source such as location.hash, document.referrer, or window.name, then writes that value into a dangerous sink like innerHTML, document.write, or eval without sanitization.

The changed scope condition indicates the injected script can affect resources outside the vulnerable AEM component. In AEM deployments, this typically means script execution in an authoring context can reach author-session cookies, published content, or embedded iframes hosting third-party origins. The EPSS score of 0.249% reflects a low near-term exploitation probability, but the presence of authenticated author users elevates practical risk for content-management workflows.

Root Cause

The root cause is insufficient sanitization of untrusted data flowing from a DOM source to a DOM sink within AEM's client-side JavaScript. Adobe has not published the exact vulnerable component. Refer to the Adobe Security Advisory APSB26-98 for authoritative technical detail.

Attack Vector

An attacker crafts a URL or webpage containing malicious JavaScript payloads embedded in DOM-accessible parameters. The attacker delivers the link to an authenticated AEM user, commonly a content author or administrator, through phishing or a watering-hole page. When the victim's browser processes the URL, vulnerable client-side code writes attacker input into an executable sink, and the script runs under the victim's AEM origin. The attacker requires only low privileges (PR:L) on the target instance to stage the exploit, and user interaction is mandatory.

No public proof-of-concept exploit is available for CVE-2026-75677 at the time of publication. See Adobe Security Advisory APSB26-98 for vendor-supplied technical details.

Detection Methods for CVE-2026-75677

Indicators of Compromise

Unusual URL fragments or query parameters containing JavaScript keywords such as <script>, javascript:, onerror=, or onload= in AEM access logs.
Unexpected outbound HTTP requests from author browsers to attacker-controlled domains immediately after visiting a crafted URL.
Modification of AEM content, user preferences, or session tokens without a corresponding legitimate authoring action.

Detection Strategies

Inspect AEM Dispatcher and web-server access logs for encoded XSS payloads targeting AEM author or publish endpoints.
Deploy Content Security Policy (CSP) reporting endpoints to capture script-execution violations that indicate attempted DOM XSS.
Correlate browser-side telemetry with authenticated AEM session activity to identify anomalous JavaScript execution paths.

Monitoring Recommendations

Enable verbose logging on the AEM Dispatcher and forward events to a centralized SIEM for correlation.
Monitor author accounts for post-authentication behavioral anomalies such as bulk content changes or permission modifications following a click on an external link.
Track referrer patterns leading to AEM author URLs and flag traffic originating from unknown external domains.

How to Mitigate CVE-2026-75677

Immediate Actions Required

Apply the security update referenced in Adobe Security Advisory APSB26-98 to all AEM Cloud Service, AEM 6.5 LTS, and AMS instances.
Restrict author-console access to trusted networks and enforce VPN or zero-trust access to reduce phishing exposure.
Train content authors and administrators to avoid clicking untrusted links while authenticated to AEM.

Patch Information

Adobe released fixed versions for AEM Cloud Service and AEM 6.5 LTS (including SP1 and SP2) in advisory APSB26-98. Cloud Service customers should confirm the current release channel version. On-premise operators must apply the Service Pack or hotfix specified by Adobe for the deployed 6.5 branch. Consult the Adobe Security Advisory APSB26-98 for exact version numbers and download locations.

Workarounds

Implement a strict Content Security Policy that disallows inline scripts and restricts script-src to trusted origins to blunt DOM XSS payloads.
Configure AEM Dispatcher filter rules to reject requests containing suspicious script fragments in URLs, fragments, or query strings.
Enforce short session lifetimes and require re-authentication for privileged AEM operations until patching is complete.

bash

# Example AEM Dispatcher filter to block common XSS payload patterns
# /etc/httpd/conf.d/dispatcher.d/filters/xss_filter.any
/0100 { /type "deny" /url '*<script*' }
/0101 { /type "deny" /url '*javascript:*' }
/0102 { /type "deny" /url '*onerror=*' }
/0103 { /type "deny" /url '*onload=*' }