Advisories for Pypi/Onnx package

2026

ONNX has Null Pointer Dereference in Upsample Version Converter Adapter (Zero Inputs)

Null pointer dereference (SIGSEGV) in Upsample_6_7::adapt_upsample_6_7() (onnx/version_converter/adapters/upsample_6_7.h:31) when convert_version() processes a model with an Upsample node that has zero inputs. The adapter accesses node->inputs()[0]->sizes() without checking input count. 107-byte PoC crashes on Release build. This is the same class of bug as the Cast adapter advisory (separate report) but in a different adapter, different file, and different operator.

ONNX: TOCTOU arbitrary file read/write in save_external_dat

The save_external_data method seems to include multiple issues introducing a local TOCTOU vulnerability, an arbitrary file read/write on any system. It potentially includes a path validation bypass on Windows systems. Regarding the TOCTOU, an attacker seems to be able to overwrite victim's files via symlink following under the same privilege scope. The mentioned function can be found here: https://github.com/onnx/onnx/blob/main/onnx/external_data_helper.py#L188

ONNX: External Data Symlink Traversal

Summary Issue: Symlink traversal in external data loading allows reading files outside the model directory. Affected code: onnx/onnx/checker.cc: resolve_external_data_location used via Python onnx.external_data_helper.load_external_data_for_model. Impact: Arbitrary file read (confidentiality breach) when a model’s external data path resolves to a symlink targeting a file outside the model directory. Root Cause The function resolve_external_data_location(base_dir, location, tensor_name) intends to ensure that external data files reside within base_dir. It: Rejects empty/absolute paths Normalizes the relative …

2025

Open Neural Network Exchange (ONNX) Path Traversal Vulnerability

A vulnerability in the download_model function of the onnx/onnx framework, before and including version 1.16.1, allows for arbitrary file overwrite due to inadequate prevention of path traversal attacks in malicious tar files. This vulnerability can be exploited by an attacker to overwrite files in the user's directory, potentially leading to remote command execution.

2024

onnx allows Arbitrary File Overwrite in download_model_with_test_data

A vulnerability in the download_model_with_test_data function of the onnx/onnx framework, versions before 1.16.2, allow for arbitrary file overwrite due to inadequate prevention of path traversal attacks in malicious tar files. This vulnerability enables attackers to overwrite any file on the system, potentially leading to remote code execution, deletion of system, personal, or application files, thus impacting the integrity and availability of the system. The issue arises from the function's handling …

Onnx Directory Traversal vulnerability

Versions of the package onnx before and including 1.15.0 are vulnerable to Directory Traversal as the external_data field of the tensor proto can have a path to the file which is outside the model current directory or user-provided directory. The vulnerability occurs as a bypass for the patch added for CVE-2022-25882.

2023

Directory Traversal in onnx

Versions of the package onnx before 1.13.0 are vulnerable to Directory Traversal as the external_data field of the tensor proto can have a path to the file which is outside the model current directory or user-provided directory, for example "../../../etc/passwd"