CVE-2026-34446

MEDIUM

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

Title source: cna

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.

References (2)

[X_Refsource_Confirm] https://github.com/onnx/onnx/security/advisories/GHSA-cmw6-hcpp-c6jp

[X_Refsource_Misc] https://github.com/onnx/onnx/commit/4755f8053928dce18a61db8fec71b69c74f786cb

View Writeup ZIP pw:eip

Scores

CVSS v3 4.7

EPSS 0.0001

EPSS Percentile 1.2%

Attack Vector LOCAL

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

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact partial

Details

CWE

CWE-22 CWE-61

Status published

Products (3)

linuxfoundation/onnx < 1.21.0

onnx/onnx < 1.21.0

pypi/onnx 0 - 1.21.0PyPI

Published Apr 01, 2026

Tracked Since Apr 01, 2026