CVE-2026-34446

ONNX: Arbitrary File Read via ExternalData Hardlink Bypass in ONNX load

Published Apr 1, 2026 CVSS 3.1 · 4.7 Medium EPSS < 1% KEV · Not listed
Description
Open Neural Network Exchange (ONNX) is an open standard for machine learning interoperability. Prior to version 1.21.0, there is an issue in onnx.load, the code checks for symlinks to prevent path traversal, but completely misses hardlinks because a hardlink looks exactly like a regular file on the filesystem. This issue has been patched in version 1.21.0.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-cmw6-hcpp-c6jp ONNX: Arbitrary File Read via ExternalData Hardlink Bypass in ONNX load
History
Type Values Removed Values Added
First Time appeared Linuxfoundation
Linuxfoundation onnx
CPEs cpe:2.3:a:linuxfoundation:onnx:*:*:*:*:*:*:*:*
Vendors & Products Linuxfoundation
Linuxfoundation onnx
Type Values Removed Values Added
First Time appeared Onnx
Onnx onnx
Vendors & Products Onnx
Onnx onnx
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Open Neural Network Exchange (ONNX) is an open standard for machine learning interoperability. Prior to version 1.21.0, there is an issue in onnx.load, the code checks for symlinks to prevent path traversal, but completely misses hardlinks because a hardlink looks exactly like a regular file on the filesystem. This issue has been patched in version 1.21.0.
Title ONNX: Arbitrary File Read via ExternalData Hardlink Bypass in ONNX load
Weaknesses CWE-22
CWE-61
References
Metrics cvssV3_1

{'score': 4.7, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Apr 2, 2026, 2:10 PM
Reserved
Mar 27, 2026, 6:18 PM
Status
Analyzed
Published
Apr 1, 2026, 6:16 PM
Modified
Jun 17, 2026, 10:39 AM
Severity
Moderate
Public date
Apr 1, 2026, 5:37 PM