CVE-2025-33253: Nemo toolkit NVIDIA NeMo Framework Deserializes Untrusted Vulnerability

HIGH
Advisory Identifier: GHSA-hvjw-vp7g-39h5
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CVSS 7.8
CWE-502
Published
Advisory Summary

CVE-2025-33253 is a HIGH (CVSS 7.8) nvidia nemo framework deserializes untrusted vulnerability (CWE-502: Deserialization of Untrusted Data) affecting Nemo toolkit libraries in the PyPI ecosystem. The issue involves nvidia nemo framework deserializes untrusted data. Remediation is available by upgrading affected packages to version 2.6.1.

CVE-2025-33253 at a Glance

CVE Identifier CVE-2025-33253
GHSA Identifier GHSA-hvjw-vp7g-39h5
Severity HIGH
CVSS v3.1 Base Score 7.8
CWE Classification CWE-502: Deserialization of Untrusted Data
Affected Product Nemo toolkit
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 7.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2025-33253

To remediate this vulnerability, upgrade all affected Nemo toolkit dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

nemo-toolkit fixed: 2.6.1 
pip install nemo-toolkit>=2.6.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show nemo-toolkit

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2025-33253, inspect your installed packages using pip:

pip show nemo-toolkit

Analyze the terminal output to locate any version of Nemo toolkit in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.6.1), your application is affected.

Note: The pip show nemo-toolkit command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-502: Deserialization of Untrusted Data, where the product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid. In Nemo toolkit, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

NVIDIA NeMo Framework contains a vulnerability where an attacker could cause remote code execution by convincing a user to load a maliciously crafted file. A successful exploit of this vulnerability might lead to code execution, denial of service, information disclosure, and data tampering.

CVE-2025-33253 Affected Nemo toolkit Versions

1 component(s)
Fixed Versions:
2.6.1
Product / Package Ecosystem Affected Versions Fixed Version
nemo-toolkit
pypi/nemo-toolkit
PyPI
< 2.6.1
2.6.1

References

NVD — CVE-2025-33253 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-33253
Nemo toolkit Source Repository REPOSITORY
https://github.com/NVIDIA-NeMo/NeMo
nvidia.custhelp.com/app/answers/detail/... WEB
https://nvidia.custhelp.com/app/answers/detail/a_id/5762
CVE Official Record — CVE-2025-33253 CVE
https://www.cve.org/CVERecord?id=CVE-2025-33253

Frequently Asked Questions

What is CVE-2025-33253?
CVE-2025-33253 is a security vulnerability in Nemo toolkit involving NVIDIA NeMo Framework Deserializes Untrusted Data under CWE-502: Deserialization of Untrusted Data.
Which Nemo toolkit versions are affected?
Affected versions include releases prior to 2.6.1 across affected packages: nemo-toolkit.
What version fixes CVE-2025-33253?
Upgrading to 2.6.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is nemo-toolkit affected?
Yes, nemo-toolkit is affected in releases prior to 2.6.1. Upgrade your dependency to 2.6.1 or later.
What is the CVSS score of CVE-2025-33253?
CVE-2025-33253 has a CVSS v3.1 base score of 7.8 (HIGH) with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2025-33253?
CVE-2025-33253 is classified under CWE-502: Deserialization of Untrusted Data (The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.).
How can I check PyPI dependencies for CVE-2025-33253?
Run the dependency tree command: 'pip show nemo-toolkit'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-hvjw-vp7g-39h5",
  "modified" : "2026-02-20T22:37:37Z",
  "published" : "2026-02-18T15:31:26Z",
  "aliases" : [ "CVE-2025-33253" ],
  "summary" : "NVIDIA NeMo Framework Deserializes Untrusted Data",
  "details" : "NVIDIA NeMo Framework contains a vulnerability where an attacker could cause remote code execution by convincing a user to load a maliciously crafted file. A successful exploit of this vulnerability might lead to code execution, denial of service, information disclosure, and data tampering.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "nemo-toolkit"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.6.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-33253"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/NVIDIA-NeMo/NeMo"
  }, {
    "type" : "WEB",
    "url" : "https://nvidia.custhelp.com/app/answers/detail/a_id/5762"
  }, {
    "type" : "WEB",
    "url" : "https://www.cve.org/CVERecord?id=CVE-2025-33253"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-502" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-02-20T22:37:17Z",
    "nvd_published_at" : "2026-02-18T14:16:04Z"
  }
}