CVE-2026-75708: Adobe Experience Manager XSS Vulnerability

CVE-2026-75708 Overview

CVE-2026-75708 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 arbitrary JavaScript within the victim's browser session. Successful exploitation requires user interaction — the victim must visit a crafted webpage — and the attacker must hold low-level privileges on the target application. The vulnerability has a changed scope, meaning execution can affect components beyond the initially vulnerable one. Adobe published the fix in security advisory APSB26-98, which addresses both AEM Cloud Service and AEM 6.5 LTS releases. The issue is tracked under CWE-79.

Critical Impact
Successful exploitation allows attackers to execute JavaScript in the victim's browser context, enabling session hijacking, credential theft, or unauthorized actions within AEM.

Affected Products

Adobe Experience Manager (all versions prior to the APSB26-98 patch)
Adobe Experience Manager Cloud Service (AEM CS)
Adobe Experience Manager 6.5 LTS (including SP1 and SP2)

Discovery Timeline

2026-09-08 - CVE-2026-75708 published to NVD
2026-09-10 - Last updated in NVD database

Technical Details for CVE-2026-75708

Vulnerability Analysis

CVE-2026-75708 is a client-side XSS flaw rooted in unsafe handling of attacker-controlled data by AEM's JavaScript execution paths. Unlike reflected or stored XSS, DOM-based XSS never sends the malicious payload to the server. Instead, a vulnerable client-side script reads data from a source such as document.location, document.URL, or window.name and passes it to a dangerous sink such as innerHTML, document.write, or eval without proper sanitization.

Because the CVSS scope is changed, code executed in the browser context can affect resources beyond the vulnerable component, including authenticated AEM author sessions, editorial workflows, and content publishing pipelines. Exploitation requires an authenticated user with low privileges to visit a crafted URL, which limits mass exploitation but remains practical for targeted phishing against content authors and administrators.

Root Cause

The root cause is improper neutralization of input during web page generation on the client side, categorized under CWE-79. An AEM JavaScript component reads attacker-influenced data from a DOM source and writes it into a sink that interprets HTML or JavaScript. Adobe has not publicly disclosed the specific vulnerable component in APSB26-98 beyond the classification.

Attack Vector

The attack proceeds in three stages. First, the attacker crafts a URL containing a malicious payload in a fragment, query parameter, or other DOM-readable source. Second, the attacker delivers the URL to an authenticated AEM user through phishing or a malicious webpage. Third, when the victim's browser processes the page, the vulnerable client-side script parses the attacker-controlled source and writes it to a dangerous sink, executing JavaScript under the AEM origin.

No public proof-of-concept or exploit code is available at the time of publication. Refer to the Adobe Security Advisory APSB26-98 for vendor-supplied technical details.

Detection Methods for CVE-2026-75708

Indicators of Compromise

Anomalous AEM authoring or admin sessions initiating outbound requests to unfamiliar domains shortly after a user clicks an external link.
HTTP access logs showing AEM URLs with unusual fragment identifiers, javascript: schemes, or encoded <script> payloads.
Unexpected content modifications, user account changes, or workflow state transitions performed by legitimate accounts without corresponding user activity.

Detection Strategies

Deploy a Content Security Policy (CSP) in report-only mode to surface script violations from AEM author and publish instances.
Instrument web application firewalls (WAFs) with rules that flag DOM-XSS payload signatures such as onerror=, javascript:, and encoded script tags in AEM request URIs.
Correlate authenticated AEM session activity with browser telemetry to identify script execution that does not match user intent.

Monitoring Recommendations

Enable verbose logging on AEM Dispatcher and reverse proxies to capture full request URIs including fragments where feasible.
Monitor for privilege changes, replication agent modifications, and JCR node writes performed by author accounts outside business hours.
Ingest AEM access, request, and audit logs into a centralized SIEM to enable historical hunting for crafted URL patterns.

How to Mitigate CVE-2026-75708

Immediate Actions Required

Apply the fixes published in Adobe Security Advisory APSB26-98 to AEM Cloud Service and AEM 6.5 LTS instances.
Review AEM author account inventory and remove or restrict low-privilege accounts that no longer require access.
Train content authors and administrators to avoid clicking untrusted links while authenticated to AEM.

Patch Information

Adobe addressed CVE-2026-75708 in security bulletin APSB26-98. Customers running AEM Cloud Service receive fixes through the managed release cycle. On-premises operators of AEM 6.5 LTS (including SP1 and SP2) must install the service pack or hotfix referenced in the advisory. Verify patch installation using the AEM Package Manager and confirm the OSGi bundle versions match those listed in the advisory.

Workarounds

Enforce a strict Content Security Policy (CSP) that disallows inline scripts and restricts script sources to trusted origins.
Configure the AEM Dispatcher to reject requests containing suspicious characters or encoded script payloads in query strings.
Require authors to use isolated browser profiles or dedicated workstations for AEM administrative work, reducing exposure to malicious third-party pages.

bash

# Configuration example: minimal CSP header for AEM author instance
# Add via Dispatcher or reverse proxy in front of AEM
Header always set Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'; frame-ancestors 'self'"