CVE-2026-81476: Dell OpenManage Server Administrator RCE

CVE-2026-81476 Overview

CVE-2026-81476 is an OS Command Injection vulnerability in Dell OpenManage Server Administrator (OMSA) versions prior to 11.1.0.3. The flaw stems from improper neutralization of special elements passed to an operating system command [CWE-78]. An unauthenticated remote attacker can exploit the weakness to achieve arbitrary command execution on the affected host. Dell OMSA is widely deployed on PowerEdge servers to provide out-of-band and in-band systems management, making the vulnerable service a high-value target within enterprise data centers.

Critical Impact
Successful exploitation grants remote code execution on the server running OMSA, exposing full confidentiality, integrity, and availability of the underlying host.

Affected Products

Dell OpenManage Server Administrator (OMSA) versions prior to 11.1.0.3
Dell PowerEdge servers with vulnerable OMSA installations
Windows and Linux hosts running the affected OMSA agent

Discovery Timeline

2026-09-17 - CVE-2026-81476 published to NVD
2026-09-17 - Last updated in NVD database

Technical Details for CVE-2026-81476

Vulnerability Analysis

Dell OpenManage Server Administrator exposes a network-accessible management interface used to configure hardware, monitor sensors, and orchestrate firmware operations on PowerEdge servers. The vulnerability resides in a request-handling path that constructs an operating system command using attacker-controlled input without adequate neutralization of shell metacharacters. Because OMSA runs with elevated privileges on the host, injected commands execute in that privileged context.

The issue is classified under CWE-78: Improper Neutralization of Special Elements used in an OS Command. Exploitation requires no authentication and no user interaction, but Dell describes higher attack complexity, suggesting specific preconditions or timing constraints must be met for reliable exploitation.

Root Cause

The root cause is unsafe composition of shell command strings from untrusted input. Special characters such as ;, |, `, $(), and newline sequences are not stripped or escaped before the resulting command is passed to a system shell or command interpreter. As a result, attacker-supplied data is interpreted as command syntax rather than opaque parameters.

Attack Vector

The attack vector is network-based and unauthenticated. An adversary with reachability to the OMSA management port sends a crafted HTTP request whose parameters contain shell metacharacters and appended commands. When OMSA processes the request, the shell parses the injected payload and executes the attacker's commands. Refer to the Dell Security Update for OMSA (DSA-2026-403) for vendor-supplied technical details.

Detection Methods for CVE-2026-81476

Indicators of Compromise

Unexpected child processes spawned by the OMSA service account, including shells such as cmd.exe, powershell.exe, /bin/sh, or /bin/bash.
OMSA web server access logs containing shell metacharacters (;, |, &&, `, $() inside query strings or POST bodies.
Outbound network connections initiated by OMSA processes to unfamiliar external hosts.
New scheduled tasks, cron entries, or service accounts created shortly after OMSA request activity.

Detection Strategies

Baseline the process tree for the OMSA service and alert on any deviation that involves interactive shells or scripting engines.
Inspect HTTP requests to OMSA management ports (default TCP 1311) for suspicious characters and command-like tokens.
Correlate authentication-free requests to OMSA endpoints with subsequent process creation events on the same host.

Monitoring Recommendations

Forward OMSA access logs and host process telemetry to a centralized analytics platform for cross-source correlation.
Monitor for privilege-escalated command execution originating from the OMSA installation directory.
Alert on egress traffic from management servers to non-corporate destinations, which often indicates post-exploitation activity.

How to Mitigate CVE-2026-81476

Immediate Actions Required

Upgrade Dell OpenManage Server Administrator to version 11.1.0.3 or later on all managed hosts.
Restrict network access to the OMSA management interface to trusted administrative subnets only.
Audit hosts running OMSA for unexpected processes, accounts, or persistence artifacts created since the service was last patched.

Patch Information

Dell has released a fixed version of OMSA that addresses the OS command injection flaw. Apply the update documented in the Dell Security Update for OMSA (DSA-2026-403). Verify the installed build reports version 11.1.0.3 or newer after upgrade.

Workarounds

Block inbound traffic to OMSA management ports (TCP 1311 by default) at the host firewall except from a defined administrative jump host.
Disable the OMSA remote management service on systems that do not require network-based administration.
Place OMSA-managed hosts behind a segmented management VLAN with strict access control lists until patching is complete.

bash

# Example: restrict OMSA management port to a single admin host on Linux
iptables -A INPUT -p tcp --dport 1311 -s 10.0.0.10 -j ACCEPT
iptables -A INPUT -p tcp --dport 1311 -j DROP