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ONNX Untrusted Model Repository Warnings Suppressed by silent=True in onnx.hub.load() — Silent Supply-Chain Attack

High severity GitHub Reviewed Published Mar 16, 2026 in onnx/onnx • Updated Apr 6, 2026

Package

pip onnx (pip)

Affected versions

<= 1.20.1

Patched versions

1.21.0

Description

What's the issue

Passing silent=True to onnx.hub.load() kills all trust warnings and user prompts. This means a model can be downloaded from any unverified GitHub repo with zero user awareness.

if not _verify_repo_ref(repo) and not silent:
    # completely skipped when silent=True
    print("The model repo... is not trusted")
    if input().lower() != "y":
        return None

On top of that, the SHA256 integrity check is useless here — it validates against a manifest that lives in the same repo the attacker controls, so the hash will always match.

Impact

Any pipeline using hub.load() with silent=True and an external repo string is silently loading whatever the repo owner ships. If that model executes arbitrary code on load, the attacker has access to the machine.

Resolved by removing the feature

References

References

@javier-intel javier-intel published to onnx/onnx Mar 16, 2026
Published to the GitHub Advisory Database Mar 16, 2026
Reviewed Mar 16, 2026
Published by the National Vulnerability Database Mar 18, 2026
Last updated Apr 6, 2026

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
None
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(1st percentile)

Weaknesses

Insufficient Verification of Data Authenticity

The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data. Learn more on MITRE.

Download of Code Without Integrity Check

The product downloads source code or an executable from a remote location and executes the code without sufficiently verifying the origin and integrity of the code. Learn more on MITRE.

Protection Mechanism Failure

The product does not use or incorrectly uses a protection mechanism that provides sufficient defense against directed attacks against the product. Learn more on MITRE.

CVE ID

CVE-2026-28500

GHSA ID

GHSA-hqmj-h5c6-369m

Source code

Credits

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