CVE-2026-24183: NVIDIA Cumulus Linux Privilege Escalation

CVE-2026-24183 Overview

CVE-2026-24183 is a local privilege escalation vulnerability in NVIDIA Cumulus Linux. The flaw resides in the user management component and stems from improper privilege management [CWE-250]. An unprivileged local user with existing access to an affected system can abuse the weakness to elevate privileges. Successful exploitation results in full compromise of the affected switch operating system, including confidentiality, integrity, and availability impacts. NVIDIA published details of this issue through its product security repository, and the CVE was disclosed publicly on August 18, 2026.

Critical Impact
A local unprivileged user can escalate to elevated privileges on NVIDIA Cumulus Linux, gaining full control of the switch operating system and any network functions it manages.

Affected Products

NVIDIA Cumulus Linux (network operating system for data center switches)
User management component of Cumulus Linux
Refer to the NVIDIA product security advisory for the authoritative list of affected versions

Discovery Timeline

2026-08-18 - CVE-2026-24183 published to the National Vulnerability Database
2026-08-20 - Last updated in NVD database

Technical Details for CVE-2026-24183

Vulnerability Analysis

CVE-2026-24183 is classified under [CWE-250], Execution with Unnecessary Privileges. The weakness lives in the user management subsystem of NVIDIA Cumulus Linux, the Linux-based network operating system that runs on NVIDIA and third-party data center switches. The component grants operations more privilege than required, allowing an authenticated local user to cross a security boundary that should isolate administrative functions. Because the attack vector is local and requires only low privileges with no user interaction, any account that reaches a shell on the switch is a viable staging point. A successful exploit yields high impact to confidentiality, integrity, and availability of the underlying operating system.

Root Cause

The root cause is improper privilege management in a user management workflow. A privileged operation is exposed to, or executed on behalf of, an account that lacks the corresponding authorization. NVIDIA has not published low-level technical details of the flawed code path in the public advisory.

Attack Vector

Exploitation requires local access and a valid low-privileged account on the switch. The attacker interacts with the vulnerable user management functionality to trigger execution with elevated privileges. No user interaction is required from an administrator, and the scope remains unchanged, meaning the attacker gains privileges within the same security authority. See the NVIDIA security advisory for vendor-supplied technical detail.

Detection Methods for CVE-2026-24183

Indicators of Compromise

Unexpected creation, modification, or deletion of local user accounts on Cumulus Linux switches, particularly accounts added to sudo, nvapply, or other administrative groups
Anomalous invocations of user management utilities such as useradd, usermod, passwd, or NVUE configuration commands from non-administrative shells
Sudden appearance of new SSH authorized_keys entries for existing accounts in /home/*/.ssh/
Shell sessions from low-privileged accounts that transition to UID 0 without a corresponding authorized sudo audit entry

Detection Strategies

Enable and centralize auditd rules covering /etc/passwd, /etc/shadow, /etc/group, and /etc/sudoers.d/ on all Cumulus switches
Forward switch syslog, NVUE, and audit logs to a SIEM and alert on privilege changes performed by non-administrative accounts
Baseline the expected set of local accounts and administrative group members on each switch, then alert on deviations

Monitoring Recommendations

Ingest Cumulus Linux telemetry into a centralized data lake for cross-switch correlation and long-term retention
Monitor for lateral movement from management jump hosts to network devices, since a local-only vulnerability requires prior foothold
Track authentication anomalies such as low-privilege accounts logging in from unusual source hosts or at unusual times

How to Mitigate CVE-2026-24183

Immediate Actions Required

Inventory all NVIDIA Cumulus Linux switches and cross-reference versions against the fixed release listed in the NVIDIA advisory
Apply the vendor-supplied update to affected switches during the next maintenance window
Audit local accounts on every Cumulus switch and remove any account that is not required for current operations
Restrict management-plane access to a small set of hardened jump hosts using ACLs and out-of-band management networks

Patch Information

NVIDIA has published remediation guidance in its product security repository at NVIDIA/product-security 2026/5817. Administrators should consult the advisory for the specific fixed Cumulus Linux versions and upgrade procedures. Additional record details are available at the NVD entry for CVE-2026-24183 and the CVE.org record.

Workarounds

Limit shell access to Cumulus Linux to administrators only, and disable interactive login for service or operator accounts where possible
Enforce strong authentication and TACACS+ or RADIUS-based authorization for switch access to reduce the number of viable local principals
Apply strict sudoers configuration and remove unnecessary NVUE role assignments until the patch is deployed

bash

# Example: audit local accounts and administrative group membership on Cumulus Linux
sudo getent passwd | awk -F: '$3 >= 1000 {print $1, $3, $7}'
sudo getent group sudo nvapply nvshow
sudo find /etc/sudoers.d -type f -exec ls -l {} \;
sudo auditctl -w /etc/passwd -p wa -k user_mgmt
sudo auditctl -w /etc/shadow -p wa -k user_mgmt
sudo auditctl -w /etc/sudoers.d/ -p wa -k user_mgmt