CVE-2026-24149: NVIDIA Megatron-LM RCE Vulnerability

CVE-2026-24149 Overview

CVE-2026-24149 is a code injection vulnerability affecting NVIDIA Megatron-LM across all platforms. The vulnerability exists within a script component where malicious data crafted by an attacker can trigger a code injection issue. Successful exploitation of this vulnerability may result in arbitrary code execution, privilege escalation, information disclosure, and data tampering.

NVIDIA Megatron-LM is a large-scale transformer model framework used extensively in deep learning and AI research environments. This vulnerability poses significant risk to organizations utilizing Megatron-LM for training large language models and other AI workloads.

Critical Impact

Successful exploitation enables attackers to execute arbitrary code, escalate privileges, access sensitive information, and tamper with data on affected systems running NVIDIA Megatron-LM.

Affected Products

• NVIDIA Megatron-LM (all platforms)

Discovery Timeline

• 2026-02-03 - CVE-2026-24149 published to NVD
• 2026-02-04 - Last updated in NVD database

Technical Details for CVE-2026-24149

Vulnerability Analysis

This vulnerability is classified as CWE-94 (Improper Control of Generation of Code), commonly known as Code Injection. The flaw resides within a script component of NVIDIA Megatron-LM that fails to properly validate or sanitize input data before processing it. When an attacker supplies specially crafted malicious data, the vulnerable script may interpret portions of that data as executable code rather than treating it as data.

The local attack vector means an attacker requires some level of access to the target system, though only low privileges are needed to exploit the vulnerability. Once exploited, the impact spans all three security pillars—confidentiality, integrity, and availability—allowing attackers to read sensitive data, modify system configurations or model data, and potentially disrupt AI training operations.

Root Cause

The root cause of CVE-2026-24149 is improper input validation within a script component of NVIDIA Megatron-LM. The vulnerable script processes external data without adequate sanitization, allowing attacker-controlled content to be interpreted as executable code. This type of vulnerability typically occurs when dynamic code evaluation functions or shell commands incorporate untrusted input without proper escaping or validation mechanisms.

Attack Vector

The attack requires local access to a system running NVIDIA Megatron-LM. An attacker with low-privilege access can craft malicious data that, when processed by the vulnerable script, results in code injection. The attack does not require user interaction and can be executed directly by an authenticated local user.

Exploitation involves preparing malicious data payloads designed to escape the expected data context and inject executable code. When the vulnerable script processes this data, the injected code executes with the privileges of the Megatron-LM process, potentially allowing the attacker to escalate privileges, exfiltrate training data or model weights, or compromise the integrity of AI workloads.

For detailed technical information about the vulnerability mechanism, refer to the NVD CVE-2026-24149 Details and CVE.org Record for CVE-2026-24149.

Detection Methods for CVE-2026-24149

Indicators of Compromise

• Unexpected script execution or child processes spawned by Megatron-LM scripts
• Anomalous file access patterns, particularly reads or writes to sensitive directories outside the normal Megatron-LM workflow
• Unusual network connections originating from processes associated with Megatron-LM
• Modified or corrupted training data files or model checkpoints

Detection Strategies

• Monitor process execution chains for Megatron-LM scripts spawning unexpected child processes or shell commands
• Implement file integrity monitoring on Megatron-LM installation directories and training data repositories
• Deploy endpoint detection and response (EDR) solutions to identify suspicious code execution patterns
• Enable verbose logging for Megatron-LM script execution to capture input data anomalies

Monitoring Recommendations

• Configure audit logging for all Megatron-LM script executions, capturing command-line arguments and input sources
• Establish baseline behavior for Megatron-LM processes and alert on deviations from normal execution patterns
• Monitor for privilege escalation attempts following Megatron-LM script execution
• Track data file modifications and correlate with script execution events

How to Mitigate CVE-2026-24149

Immediate Actions Required

• Audit and restrict local access to systems running NVIDIA Megatron-LM to authorized personnel only
• Review and validate all input data sources used by Megatron-LM scripts before processing
• Implement network segmentation to isolate AI training infrastructure from general-purpose systems
• Apply the principle of least privilege to Megatron-LM process execution accounts

Patch Information

Organizations should monitor NVIDIA's official security bulletins and the Megatron-LM GitHub repository for security patches addressing CVE-2026-24149. Apply vendor-provided patches as soon as they become available. For the latest patch information, consult the NVD CVE-2026-24149 Details.

Workarounds

• Restrict execution permissions on vulnerable scripts to trusted administrators only
• Implement strict input validation on all data processed by Megatron-LM scripts using allowlists where possible
• Run Megatron-LM processes in containerized environments with reduced capabilities and limited filesystem access
• Disable or remove unnecessary script components that are not required for your specific Megatron-LM deployment

# Example: Restrict script permissions and execution context
chmod 750 /path/to/megatron-lm/scripts/*.py
chown root:megatron-admins /path/to/megatron-lm/scripts/*.py

# Run Megatron-LM with reduced privileges using a dedicated service account
sudo -u megatron-service python /path/to/megatron-lm/train.py --config secure_config.yaml