CVE-2026-75726: Adobe Experience Manager Auth Bypass Flaw

CVE-2026-75726 Overview

CVE-2026-75726 affects Adobe Experience Manager (AEM) and stems from improper input validation [CWE-20]. A low-privileged attacker can bypass security controls to gain limited unauthorized write access. Exploitation requires user interaction, such as a victim visiting a maliciously crafted URL or interacting with a compromised web page.

The vulnerability impacts both AEM Cloud Service and AEM 6.5 LTS deployments. Adobe published the security advisory tracking this issue as APSB26-98.

Critical Impact
A low-privileged, authenticated attacker can bypass a security feature in Adobe Experience Manager and obtain limited write access when a victim interacts with an attacker-controlled URL or page.

Affected Products

Adobe Experience Manager Cloud Service (AEM CS)
Adobe Experience Manager 6.5 LTS (base release)
Adobe Experience Manager 6.5 LTS Service Packs SP1 and SP2

Discovery Timeline

2026-09-08 - CVE-2026-75726 published to NVD
2026-09-10 - Last updated in NVD database

Technical Details for CVE-2026-75726

Vulnerability Analysis

CVE-2026-75726 is an Improper Input Validation flaw [CWE-20] in Adobe Experience Manager. AEM fails to validate specific input before acting on it, which allows a security control to be bypassed under the right conditions. The result is a limited integrity impact: an attacker gains unauthorized write access to resources they should not be able to modify.

The issue requires both authentication and user interaction. An attacker needs low-privileged access to the AEM instance and must convince a victim, typically an authenticated AEM user with higher privileges, to visit a crafted URL or interact with a compromised page. Confidentiality and availability are not directly affected, and the scope of the bypass is confined to the AEM application.

Adobe categorizes this issue in its APSB26-98 bulletin and rates the practical risk as low. The EPSS score of 0.381% reflects a low near-term probability of observed exploitation.

Root Cause

The root cause is insufficient validation of attacker-controlled input flowing into a security-sensitive code path in AEM. Because AEM does not reject or normalize the malformed input, a security feature intended to enforce access restrictions is bypassed. Adobe has not published detailed technical internals of the affected component.

Attack Vector

The attack is network-based and leverages a client-side interaction pattern typical of cross-site request or reflected-parameter abuse. A low-privileged attacker crafts a URL or web page that, when loaded by a victim in an authenticated AEM session, triggers the vulnerable request against the AEM backend. The backend fails to validate the request and performs a limited write operation on behalf of the victim.

No public proof-of-concept, exploit code, or in-the-wild exploitation has been reported. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

Detection Methods for CVE-2026-75726

Indicators of Compromise

Unexpected write, update, or publish actions in AEM audit logs performed by low-privileged accounts or through unusual referrer chains.
Requests to AEM endpoints containing malformed or unexpected parameters that precede content or configuration modifications.
Off-hours or bulk modification events initiated from user sessions that normally perform read-only activity.

Detection Strategies

Enable and centralize AEM access.log, request.log, and Sling audit logs, then alert on write operations correlated with external referrers or suspicious URLs.
Compare user role assignments against the actions those users perform, flagging any write operation executed by an account whose role does not authorize it.
Hunt for repeated 4xx or 5xx responses on Sling servlet endpoints followed by a successful 200 write response from the same session.

Monitoring Recommendations

Ship AEM logs into a centralized analytics platform and build baseline profiles per author role to surface deviations.
Monitor Dispatcher and CDN layers for crafted URL patterns aimed at AEM author or publish instances.
Track outbound email, notification, or workflow activity that could indicate a victim was lured to a crafted URL.

How to Mitigate CVE-2026-75726

Immediate Actions Required

Apply the Adobe security update referenced in bulletin APSB26-98 to all AEM Cloud Service and AEM 6.5 LTS instances, including SP1 and SP2.
Review AEM user and group memberships and remove unused low-privileged author accounts that could be leveraged for this attack.
Enforce short session lifetimes and require re-authentication for sensitive AEM write operations.

Patch Information

Adobe has released fixes for AEM Cloud Service and AEM 6.5 LTS. Refer to the Adobe Experience Manager Security Advisory APSB26-98 for the current patched build numbers and upgrade instructions for each track.

Workarounds

Restrict access to AEM author instances to trusted networks or VPN-only paths until the patch is applied.
Harden the AEM Dispatcher and web tier to reject requests with unexpected parameters or suspicious URL structures targeting write endpoints.
Require anti-CSRF tokens and enforce SameSite cookie attributes on AEM sessions to reduce the impact of malicious cross-site interactions.

bash

# Example: restrict AEM author access at the Dispatcher level to internal networks only
<VirtualHost *:443>
    ServerName author.example.com
    <Location />
        Require ip 10.0.0.0/8
        Require ip 192.168.0.0/16
    </Location>
</VirtualHost>