CVE-2026-34446 MEDIUM

CVE-2026-34446: ONNX: Arbitrary File Read via ExternalData Hardlink Bypass in ONNX load

Vendor Onnx
Product onnx
Weakness CWE-22 · Path traversal
Published April 1, 2026
Last update April 2, 2026

CVSS base score

4.7/10
Attack vector Local
Attack complexity High
Privileges required None
User interaction Required
Confidentiality High
Integrity None

CVSS vector

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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

April 1, 2026 CVE published
April 2, 2026 Record updated