CVE-2025-33205: Nvidia Nemo RCE Vulnerability

CVE-2025-33205 Overview

CVE-2025-33205 affects the NVIDIA NeMo framework, a toolkit used to build and train generative AI and large language models. The vulnerability resides in a predefined variable that allows an attacker to cause inclusion of functionality from an untrusted control sphere [CWE-829]. A successful exploit may lead to arbitrary code execution in the context of the NeMo process. The flaw requires local access, low privileges, and user interaction, which limits remote exploitation but still exposes shared AI development environments and multi-tenant training infrastructure.

Critical Impact
Successful exploitation can lead to code execution, compromising confidentiality, integrity, and availability of the NeMo host environment.

Affected Products

NVIDIA NeMo framework (all supported platforms prior to the patched release)
Deployments using NeMo for large language model training and inference
AI/ML pipelines that load NeMo modules referencing the vulnerable predefined variable

Discovery Timeline

2025-11-25 - CVE-2025-33205 published to the National Vulnerability Database (NVD)
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-33205

Vulnerability Analysis

The vulnerability is classified as Inclusion of Functionality from Untrusted Control Sphere [CWE-829]. NVIDIA NeMo relies on a predefined variable whose value influences which code or module is loaded at runtime. An attacker with local access can manipulate the referenced source so that NeMo loads attacker-controlled functionality instead of the intended trusted component.

Because NeMo executes machine learning workflows with the privileges of the invoking user, loaded functionality runs with those same privileges. The attack requires user interaction, which typically means an operator must launch a training or inference workflow that consumes the tampered predefined variable. The result is arbitrary code execution within the NeMo runtime.

Root Cause

The root cause is unsafe use of a predefined variable that resolves to an external or attacker-influenceable location. When NeMo consumes this variable during initialization or module resolution, it does not sufficiently validate that the referenced code originates from a trusted control sphere. This permits substitution of legitimate functionality with malicious code.

Attack Vector

Exploitation requires local access to the system running NeMo and low-privileged access to the file system or environment used by the framework. The attacker plants or modifies the resource resolved by the predefined variable. When a legitimate user runs a NeMo workflow that dereferences the variable, the malicious functionality executes in that user's context. Refer to the NVIDIA Support Response for authoritative details.

No public proof-of-concept has been published, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

Detection Methods for CVE-2025-33205

Indicators of Compromise

Unexpected modifications to files, directories, or environment variables referenced by NeMo predefined variables
NeMo Python processes spawning shells, network utilities, or other non-ML child processes
Outbound network connections from NeMo workflows to unfamiliar hosts during training or inference
New or altered Python modules in paths consumed by NeMo initialization routines

Detection Strategies

Monitor process lineage for python and NeMo entrypoints spawning unexpected binaries or interpreters
Track write events to directories and configuration paths that NeMo resolves from predefined variables
Baseline expected module imports for NeMo workflows and alert on deviations
Correlate user session activity with NeMo execution to identify workflows launched shortly after suspicious file changes

Monitoring Recommendations

Enable file integrity monitoring on NeMo installation directories and configuration files
Log environment variable values passed to NeMo processes for forensic review
Aggregate host telemetry into a centralized data lake to enable retrospective hunting across AI/ML hosts
Alert on privilege changes or credential access following NeMo process activity

How to Mitigate CVE-2025-33205

Immediate Actions Required

Apply the NeMo update described in the NVIDIA Support Response as soon as feasible
Restrict local access to hosts running NeMo to authorized ML engineers and service accounts
Audit and lock down write permissions on directories and files resolved by NeMo predefined variables
Review recent NeMo workflow executions for signs of tampered inputs or unexpected module loading

Patch Information

NVIDIA has published a security bulletin for this issue. Consult the NVIDIA Support Response for the fixed NeMo versions and upgrade guidance. Additional metadata is available in the NVD CVE-2025-33205 record and the CVE.org record.

Workarounds

Run NeMo workloads under dedicated, least-privileged user accounts isolated from other tenants
Explicitly set and validate the affected predefined variable to a trusted, read-only path before invoking NeMo
Execute NeMo inside containers with read-only mounts for framework code and controlled environment variables
Enforce code signing or hash validation for any external modules loaded by NeMo workflows