CVE-2026-34446: ONNX: Arbitrary File Read via ExternalData Hardlink Bypass in ONNX load
CVE-2026-34446 · Severity: low · CVSS 3.1 · Published 2026-04-01
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.
No. Junglewise Threat Intelligence has no report of CVE-2026-34446 being exploited in the wild.
How severe is CVE-2026-34446?
Low severity, with a CVSS score of 3.1, published 1 April 2026.
Which products and versions are affected?
onnx (PyPI) ECOSYSTEM:introduced=0,fixed=1.21.0.
Is there a fix for CVE-2026-34446?
Yes. onnx (PyPI): upgrade to 1.21.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2026-34446?
Check whether you run onnx (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.