dbcve.org
Megatron LmApplication · Nvidia

CVE-2025-33248

HIGH · 7.8 CVSS v3.1 Published 2026-03-24
Fix available
A fix is available. Upgrade to 0.15.3 or later.
See remediation →
81/100
Remediation priority · High
No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
NVIDIA Megatron-LM contains a vulnerability in the hybrid conversion script where an Attacker may cause an RCE by convincing a user to load a maliciously crafted file. A successful exploit of this vulnerability may lead to code execution, escalation of privileges, information disclosure, and data tampering.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

NVIDIA Megatron-LM contains an RCE vulnerability in its hybrid conversion script. The vulnerability allows attackers to execute arbitrary code by tricking users into loading a maliciously crafted file, likely through insecure deserialization or code injection during file parsing.

MitigationUsers should avoid loading untrusted files with the hybrid conversion script until NVIDIA releases an official patch. Implement input validation and sandboxing around file loading operations as an interim control.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Megatron LmApplication
Affected:< 0.15.3

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Determine installed Megatron-LM version
    Run `pip show megatron-lm` or check the version in your environment (e.g., `python -c "import megatron; print(megatron.__version__)"` if available)
    Affected if Version is lower than 0.15.3 (e.g., 0.15.0, 0.14.0, etc.)
  2. Locate the hybrid conversion script
    Search for files named `hybrid_convert.py` or similar in the Megatron-LM installation directory, typically under `megatron/training/` or `tools/`
    Affected if The script exists in your installation and is accessible for use
  3. Identify if the hybrid conversion script processes external files
    Review your workflow or automation scripts to see if the hybrid conversion script is invoked with file path arguments (e.g., model权重 files, configuration files)
    Affected if The script is being used to load or convert files from any source, especially untrusted or external sources
  4. Check file loading behavior of the conversion script
    Inspect the hybrid conversion script code for deserialization calls (e.g., `pickle.load`, `torch.load`, `yaml.load` without safe loaders) or dynamic code execution patterns that handle user-supplied files
    Affected if The script uses insecure deserialization or eval/exec on file input without validation
  5. Verify input sources to the conversion workflow
    Audit logs, pipelines, or scripts that invoke the hybrid conversion script to identify if they process files from untrusted locations or external users
    Affected if Files from untrusted or unknown sources are being passed to the hybrid conversion script

You are affected if Megatron-LM version is below 0.15.3 AND you use the hybrid conversion script to load or process files, particularly from untrusted sources.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 0.15.3 or later
Fixed in 0.15.3
Interim mitigation

Users should avoid loading untrusted files with the hybrid conversion script until NVIDIA releases an official patch. Implement input validation and sandboxing around file loading operations as an interim control.

Recommended fix High confidence

0.15.3 or later

  1. Upgrade Megatron-LM to version 0.15.3 or later using pip: pip install megatron-lm>=0.15.3
  2. Verify the installed version: pip show megatron-lm
  3. Ensure any existing hybrid conversion scripts or serialized model files are re-created from trusted sources

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Megatron Lm Scoped from the published advisory
  • Consultation4.0 h
  • Implementation12.0 h
  • Testing8.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,880
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,808.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-33248 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-33248 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data