CVE-2026-24326: SAP S/4HANA Auth Bypass Vulnerability

CVE-2026-24326 Overview

A missing authorization check vulnerability has been identified in the Disconnected Operations component of SAP S/4HANA Defense & Security. This flaw allows an attacker with user privileges to call remote-enabled function modules, enabling direct updates to standard SAP database tables without proper authorization verification. The vulnerability is classified as a Missing Authorization (CWE-862) issue.

Critical Impact

Authenticated attackers can bypass authorization controls to directly modify SAP database tables, potentially compromising data integrity in defense and security-critical environments.

Affected Products

• SAP S/4HANA Defense & Security (Disconnected Operations component)

Discovery Timeline

• 2026-02-10 - CVE-2026-24326 published to NVD
• 2026-02-10 - Last updated in NVD database

Technical Details for CVE-2026-24326

Vulnerability Analysis

This vulnerability stems from insufficient authorization enforcement within the Disconnected Operations functionality of SAP S/4HANA Defense & Security. When users invoke remote-enabled function modules, the system fails to properly validate whether the calling user has the appropriate permissions to perform database update operations. This authorization bypass allows low-privileged users to execute actions beyond their intended access scope.

The vulnerability affects database integrity by permitting unauthorized modifications to standard SAP database tables. While the impact is limited to integrity (with no direct confidentiality or availability impact), in defense and security contexts, even low-integrity impacts can have significant operational consequences. The network-accessible nature of this vulnerability means it can be exploited remotely by any authenticated user without requiring user interaction.

Root Cause

The root cause is a missing authorization check (CWE-862) in the Disconnected Operations component. The affected remote-enabled function modules do not properly verify that the calling user has the necessary authorizations before allowing direct database table updates. This represents a failure to implement the principle of least privilege at the function module level.

Attack Vector

The attack vector is network-based and requires the attacker to have valid user credentials to the SAP S/4HANA Defense & Security system. Once authenticated, the attacker can:

1. Identify remote-enabled function modules within the Disconnected Operations component
2. Invoke these function modules via RFC (Remote Function Call) or similar mechanisms
3. Execute direct update operations on standard SAP database tables
4. Bypass normal authorization checks that would typically prevent such modifications

The vulnerability is exploitable without user interaction, requiring only low privileges (authenticated user access) to execute. Attackers with knowledge of SAP function module naming conventions and database table structures can craft specific calls to modify targeted data.

Detection Methods for CVE-2026-24326

Indicators of Compromise

• Unusual RFC calls to Disconnected Operations function modules from unexpected user accounts
• Database table modifications that bypass standard transaction logging
• Audit log entries showing direct table updates without corresponding authorization checks
• Elevated activity from low-privileged accounts accessing defense/security-related function modules

Detection Strategies

• Enable comprehensive SAP Security Audit Log (SM21) to capture RFC calls and function module invocations
• Configure SAP Gateway logging to monitor remote function calls to Disconnected Operations modules
• Implement SIEM rules to detect patterns of unauthorized database table modifications
• Review SAP Solution Manager for anomalous user behavior patterns

Monitoring Recommendations

• Monitor ST01 (System Trace) for authorization check failures followed by successful data modifications
• Establish baseline of normal Disconnected Operations usage and alert on deviations
• Track RFC connections and function module calls from external systems
• Review SM04 (User List) for suspicious session activity during off-hours

How to Mitigate CVE-2026-24326

Immediate Actions Required

• Apply the security patch referenced in SAP Note #3678009
• Review user authorizations for Disconnected Operations function modules
• Audit recent database table modifications for unauthorized changes
• Restrict access to remote-enabled function modules pending patch deployment

Patch Information

SAP has released a security update addressing this vulnerability. Organizations should obtain the patch through SAP Note #3678009 and follow SAP's standard patching procedures. Additional information is available on the SAP Security Patch Day portal.

Workarounds

• Implement additional authorization objects to restrict access to affected function modules
• Use SAP Gateway Access Control Lists (ACLs) to limit RFC connections to trusted systems only
• Enable enhanced logging and monitoring while awaiting patch deployment
• Consider temporarily disabling non-essential Disconnected Operations functionality in high-risk environments

* Example: Review authorization assignments via SUIM transaction
* Check users with access to critical function modules
* Report: RSUSR002 - Users by Complex Selection Criteria
* Restrict S_RFC authorization object for affected function groups