CVE-2026-34445: ONNX: Malicious ONNX models can crash servers by exploiting unprotected object settings.
CVE-2026-34445 · 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, the ExternalDataInfo class in ONNX was using Python’s setattr() function to load metadata (like file paths or data lengths) directly from an ONNX model file. It didn’t check if the "keys" in the file were valid. Due to this, an attacker could craft a malicious model that overwrites internal object properties. This issue has been patched in version 1.21.0.
No. Junglewise Threat Intelligence has no report of CVE-2026-34445 being exploited in the wild.
How severe is CVE-2026-34445?
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-2026-34445?
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-2026-34445?
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.