CVE-2026-47957 Overview
CVE-2026-47957 is a stored Cross-Site Scripting (XSS) vulnerability in Adobe Experience Manager (AEM). The flaw affects AEM versions 6.5.24, LTS SP1, 2026.04 and earlier, including AEM Cloud Service deployments. A low-privileged authenticated attacker can inject malicious JavaScript into vulnerable form fields. The payload executes in a victim's browser when they navigate to the affected page. The vulnerability carries a changed scope, meaning the impact extends beyond the vulnerable component to other security domains. Adobe published security advisory APSB26-56 to address this issue tracked under [CWE-79].
Critical Impact
Authenticated attackers can persist malicious JavaScript in form fields, hijacking sessions and executing actions in the context of any user who views the affected content.
Affected Products
- Adobe Experience Manager 6.5.24 and earlier
- Adobe Experience Manager LTS SP1 and earlier
- Adobe Experience Manager 2026.04 and earlier (including AEM Cloud Service)
Discovery Timeline
- 2026-06-09 - CVE-2026-47957 published to NVD
- 2026-06-10 - Last updated in NVD database
Technical Details for CVE-2026-47957
Vulnerability Analysis
The vulnerability is a stored XSS flaw classified under [CWE-79], Improper Neutralization of Input During Web Page Generation. AEM fails to properly sanitize user-supplied input submitted through specific form fields. Attacker-controlled JavaScript persists in the application's backing store and renders when other users load the affected page.
The scope change indicated in the CVSS vector signals that exploitation crosses a security boundary. Script execution occurs in the victim's browser session, potentially under a different privilege level than the attacker possesses. This expands the attack's reach beyond the form interface itself.
User interaction is required, meaning a victim must browse to the page containing the malicious payload. The attack vector is network-based and exploitation complexity is low.
Root Cause
The root cause is insufficient output encoding and input validation on form field data within AEM components. Untrusted input is rendered into HTML responses without proper neutralization of HTML and JavaScript control characters. This permits attacker-supplied <script> content or event handler attributes to be interpreted as code rather than data.
Attack Vector
An attacker authenticates to AEM with low privileges, typically a content author or contributor role. The attacker submits crafted input containing JavaScript into a vulnerable form field. AEM stores the payload without proper sanitization. When a victim, often a higher-privileged administrator or another site visitor, browses to the page containing the field, the browser executes the injected script. Consequences include session token theft, forced administrative actions, and content defacement.
No verified proof-of-concept code is publicly available. Refer to the Adobe Security Advisory APSB26-56 for technical details.
Detection Methods for CVE-2026-47957
Indicators of Compromise
- Unexpected <script> tags, javascript: URIs, or event handler attributes (onerror, onload, onmouseover) stored within AEM content nodes or form submissions.
- Outbound HTTP requests from authenticated user browsers to unfamiliar external domains referencing AEM session cookies.
- Anomalous administrative actions performed shortly after an administrator viewed content authored by a low-privileged user.
Detection Strategies
- Review AEM access logs for POST requests to form-handling endpoints containing HTML-encoded script payloads or suspicious character sequences.
- Audit the JCR content repository for stored values in form properties containing HTML tags or JavaScript syntax.
- Deploy a web application firewall rule that inspects form submissions for known XSS payload patterns prior to AEM processing.
Monitoring Recommendations
- Enable Content Security Policy (CSP) reporting to surface inline script execution attempts on AEM-rendered pages.
- Monitor low-privileged author accounts for unusual content modification activity targeting form components.
- Correlate authentication events with administrative configuration changes to identify potential session hijacking from XSS payloads.
How to Mitigate CVE-2026-47957
Immediate Actions Required
- Apply the security update referenced in Adobe Security Advisory APSB26-56 to all AEM instances, including LTS and Cloud Service deployments.
- Review and revoke unnecessary author and contributor permissions to reduce the population of accounts capable of exploiting the flaw.
- Audit existing content for stored payloads injected prior to patching, focusing on form fields modified by low-privileged users.
Patch Information
Adobe released fixed versions addressing CVE-2026-47957 in security bulletin APSB26-56. Administrators must upgrade AEM 6.5 deployments past version 6.5.24, AEM LTS instances past SP1, and AEM Cloud Service tenants past the 2026.04 release. Consult the Adobe Security Advisory APSB26-56 for exact build numbers and upgrade paths.
Workarounds
- Restrict form-editing privileges to trusted users until patches are applied across all environments.
- Deploy a strict Content Security Policy that disallows inline scripts and unauthorized script sources on AEM-published pages.
- Configure a web application firewall to inspect and block XSS payloads in form field submissions targeting AEM endpoints.
# Example Content Security Policy header to mitigate stored XSS execution
Content-Security-Policy: default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'; frame-ancestors 'self'
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
