id: PYSEC-2026-2240
published: "2026-04-01T18:16:30.500Z"
modified: "2026-07-13T05:50:25.772517Z"
aliases:
- CVE-2026-34445
- GHSA-538c-55jv-c5g9
details: 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.
affected:
- package:
    name: onnx
    ecosystem: PyPI
    purl: pkg:pypi/onnx
  ranges:
  - type: ECOSYSTEM
    events:
    - introduced: "0"
    - fixed: 1.21.0
  versions:
  - "0.1"
  - "0.2"
  - 0.2.1
  - 1.0.0
  - 1.0.1
  - 1.1.0
  - 1.1.1
  - 1.1.2
  - 1.10.0
  - 1.10.1
  - 1.10.2
  - 1.11.0
  - 1.12.0
  - 1.13.0
  - 1.13.1
  - 1.14.0
  - 1.14.1
  - 1.15.0
  - 1.16.0
  - 1.16.1
  - 1.16.2
  - 1.17.0
  - 1.18.0
  - 1.19.0
  - 1.19.1
  - 1.19.1rc1
  - 1.2.1
  - 1.2.2
  - 1.2.3
  - 1.20.0
  - 1.20.0rc1
  - 1.20.0rc2
  - 1.20.1
  - 1.20.1rc1
  - 1.21.0rc1
  - 1.21.0rc2
  - 1.21.0rc3
  - 1.21.0rc4
  - 1.3.0
  - 1.4.0
  - 1.4.1
  - 1.5.0
  - 1.6.0
  - 1.7.0
  - 1.8.0
  - 1.8.1
  - 1.9.0
  ecosystem_specific: {}
references:
- type: FIX
  url: https://github.com/onnx/onnx/commit/e30c6935d67cc3eca2fa284e37248e7c0036c46b
- type: FIX
  url: https://github.com/onnx/onnx/pull/7751
- type: FIX
  url: https://github.com/onnx/onnx/security/advisories/GHSA-538c-55jv-c5g9
severity:
- type: CVSS_V3
  score: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H