CVE-2026-48301: Adobe Experience Manager XSS Vulnerability

CVE-2026-48301 Overview

Adobe Experience Manager (AEM) contains a stored Cross-Site Scripting (XSS) vulnerability tracked as CVE-2026-48301. The flaw affects AEM versions 6.5.24, LTS SP1, 2026.04, and earlier releases. A low-privileged attacker can inject malicious JavaScript into vulnerable form fields. The payload executes in a victim's browser when they visit the page containing the injected field. The vulnerability carries a changed scope, meaning the impact extends beyond the vulnerable component.

Critical Impact
Authenticated attackers can persist malicious scripts in AEM form fields, executing arbitrary JavaScript in victim browsers and enabling session theft, content defacement, or pivoting to other web origins under a changed scope.

Affected Products

Adobe Experience Manager 6.5.24 and earlier
Adobe Experience Manager LTS SP1 and earlier
Adobe Experience Manager 2026.04 (AEM Cloud Service) and earlier

Discovery Timeline

2026-06-09 - CVE-2026-48301 published to NVD
2026-06-10 - Last updated in NVD database

Technical Details for CVE-2026-48301

Vulnerability Analysis

The vulnerability is a stored Cross-Site Scripting flaw classified under [CWE-79]. AEM accepts user-supplied input through form fields without sufficient output encoding or input sanitization. The malicious payload persists in the AEM repository and is rendered to other users who view the affected page.

The scope change is significant. A successful exploit can affect resources outside the vulnerable component's security context, such as authenticated sessions for adjacent applications served from the same origin. Exploitation requires low privileges and user interaction. An attacker needs only authoring-level access to inject the payload, and a victim must browse to the affected page for execution.

Root Cause

The root cause is improper neutralization of input during web page generation in AEM form-handling components. Form field values stored through low-privileged authoring workflows are reflected back into rendered HTML without context-appropriate escaping. JavaScript embedded inside attributes or script contexts therefore executes when the page loads.

Attack Vector

The attack is network-based and authenticated. An attacker with low-privileged access to an AEM authoring environment submits a form field value containing script content. AEM persists the value in its content repository. When any user, including higher-privileged administrators, browses to the page that renders the field, the malicious script runs in their browser session under the AEM origin.

No verified public exploit code is available for CVE-2026-48301. Refer to the Adobe Security Advisory APSB26-56 for technical specifics on the vulnerable form handling path.

Detection Methods for CVE-2026-48301

Indicators of Compromise

Unexpected <script> tags, javascript: URIs, or event handler attributes (onerror, onload, onmouseover) persisted in AEM form field content nodes.
HTTP POST requests to AEM authoring endpoints containing encoded script payloads from low-privileged user accounts.
Outbound browser requests from authenticated AEM sessions to attacker-controlled domains shortly after page loads.
Anomalous content modifications to form components by accounts that do not normally edit those pages.

Detection Strategies

Audit AEM content repository (/content and component nodes) for HTML or JavaScript characters in fields that should hold plain text values.
Inspect AEM access logs for POST requests carrying suspicious payloads such as <script, onerror=, or URL-encoded equivalents.
Correlate authoring activity from low-privileged accounts with subsequent abnormal browser telemetry on administrator endpoints.
Run pattern-matching scans across AEM exports for stored XSS signatures and compare against a known-good baseline.

Monitoring Recommendations

Enable verbose request logging on AEM dispatcher and publish instances and forward to a centralized SIEM for analysis.
Monitor Content Security Policy (CSP) violation reports for blocked inline script executions on AEM-hosted pages.
Track authoring account behavior for sudden increases in form field edits or off-hours content changes.
Alert on browser process child activity originating from sessions authenticated to AEM hostnames.

How to Mitigate CVE-2026-48301

Immediate Actions Required

Apply Adobe's security update referenced in advisory APSB26-56 to all affected AEM 6.5.x, LTS, and 2026.04 instances.
Review and tighten authoring permissions, removing low-privileged accounts that do not require form field editing.
Audit existing form field content for previously injected script payloads and remove malicious entries.
Force password resets for AEM author accounts if any indicators of compromise are observed.

Patch Information

Adobe addressed CVE-2026-48301 in the security update documented in Adobe Security Advisory APSB26-56. Customers running AEM Cloud Service should ensure their environment is on a release later than 2026.04. On-premises AEM 6.5 customers must install the latest service pack and cumulative fix pack. LTS SP1 customers should upgrade to the patched LTS release identified in the advisory.

Workarounds

Restrict authoring access to trusted, vetted users until the patch is deployed across all AEM instances.
Deploy a strict Content Security Policy that blocks inline scripts and unsafe event handlers on AEM-rendered pages.
Place a web application firewall in front of AEM publish and author instances with rules that filter script-like payloads in form submissions.
Disable or remove unused form components that accept rich text input from low-privileged roles.

bash

# Example CSP header to mitigate stored XSS risk on AEM-served responses
Content-Security-Policy: default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'; frame-ancestors 'self'; report-uri /csp-report