CVE-2026-23856: Dell iDRAC Service Module Privilege Escalation

CVE-2026-23856 Overview

Dell iDRAC Service Module (iSM) for Windows and Linux contains an Improper Access Control vulnerability that allows low-privileged local attackers to elevate their privileges on affected systems. This vulnerability affects critical server management infrastructure commonly deployed in enterprise data centers, making it a significant concern for organizations relying on Dell PowerEdge servers.

Critical Impact

A low-privileged attacker with local access could exploit this vulnerability to gain elevated privileges, potentially compromising the entire server infrastructure and sensitive data managed through iDRAC.

Affected Products

• Dell iDRAC Service Module (iSM) for Windows, versions prior to 6.0.3.1
• Dell iDRAC Service Module (iSM) for Linux, versions prior to 5.4.1.1

Discovery Timeline

• 2026-02-12 - CVE CVE-2026-23856 published to NVD
• 2026-02-12 - Last updated in NVD database

Technical Details for CVE-2026-23856

Vulnerability Analysis

This vulnerability stems from an Improper Access Control weakness (CWE-284) in the Dell iDRAC Service Module. The iDRAC Service Module is a lightweight optional software application that runs on the managed server's operating system and communicates with the iDRAC firmware. It provides features such as OS information, WMI information, and Lifecycle Controller jobs without requiring the iDRAC Enterprise license.

The improper access control flaw allows a local user with limited privileges to bypass intended security restrictions. Since the iSM operates with elevated system privileges to communicate with hardware management interfaces, any access control weakness in this component presents a direct path to privilege escalation.

Root Cause

The vulnerability is classified under CWE-284 (Improper Access Control), indicating that the iDRAC Service Module fails to properly restrict access to a resource or functionality that should be protected. This typically occurs when the software does not adequately verify that a user has the required permissions before granting access to protected functionality or data. In the context of iSM, this could involve insecure service configurations, improper file permissions, or inadequate validation of user requests to privileged operations.

Attack Vector

The attack requires local access to the target system, meaning an attacker must already have the ability to execute code on the server where the vulnerable iDRAC Service Module is installed. The attack complexity is low and requires no user interaction, making it straightforward to exploit once local access is obtained.

An attacker could leverage this vulnerability through various methods:

1. A compromised low-privilege user account on the server
2. Through another vulnerability that provides initial local access
3. An insider threat with legitimate but limited system access

Successful exploitation grants the attacker high-level impact to confidentiality, integrity, and availability of the system, potentially allowing complete control over the affected server and its management infrastructure.

Detection Methods for CVE-2026-23856

Indicators of Compromise

• Unexpected privilege escalation events or new administrator accounts created on systems running iDRAC Service Module
• Unusual process activity or child processes spawned by iSM-related services (iSM.exe on Windows, dcismeng on Linux)
• Modifications to iDRAC Service Module configuration files or binaries outside of scheduled maintenance windows
• Anomalous authentication attempts or successful authentications to iDRAC management interfaces from unexpected sources

Detection Strategies

• Monitor Windows Event Logs and Linux audit logs for privilege escalation attempts on servers with iSM installed
• Implement file integrity monitoring on iDRAC Service Module installation directories and configuration files
• Track process execution chains originating from iSM services for suspicious child process creation
• Alert on any unexpected changes to service account permissions associated with iDRAC components

Monitoring Recommendations

• Deploy endpoint detection and response (EDR) solutions to monitor iSM processes for behavioral anomalies
• Enable detailed audit logging on systems running vulnerable versions of the iDRAC Service Module
• Implement network segmentation to limit lateral movement from potentially compromised servers
• Regularly review access logs for iDRAC management interfaces for unauthorized access attempts

How to Mitigate CVE-2026-23856

Immediate Actions Required

• Inventory all Dell servers running iDRAC Service Module and identify versions in use
• Prioritize patching for servers in production environments and those accessible to multiple users
• Restrict local access to affected systems to only essential personnel until patches are applied
• Enable enhanced monitoring on systems running vulnerable iSM versions

Patch Information

Dell has released security updates to address this vulnerability. Organizations should update to the following versions or later:

• Windows: Dell iDRAC Service Module (iSM) version 6.0.3.1 or later
• Linux: Dell iDRAC Service Module (iSM) version 5.4.1.1 or later

For detailed patch information and download links, refer to the Dell Security Update Advisory.

Workarounds

• Limit local user access on affected servers to only trusted administrators until patches can be applied
• Implement strict application whitelisting to prevent unauthorized code execution
• Consider temporarily disabling the iDRAC Service Module if the functionality is not critical, though this will limit certain iDRAC features
• Enforce network segmentation to isolate management networks and reduce the attack surface

# Verify current iDRAC Service Module version on Windows
wmic product where "name like '%iDRAC%'" get name,version

# Verify current iDRAC Service Module version on Linux
rpm -qa | grep -i idrac
# or
dpkg -l | grep -i idrac

# Check iSM service status on Linux
systemctl status dcismeng