ONNX up to 1.21.0 Version Converter Adapters upsample_6_7.h adapt_upsample_6_7 inputs null pointer dereference

Summaryinfo

A vulnerability marked as problematic has been reported in ONNX up to 1.21.0. This affects the function Upsample_6_7::adapt_upsample_6_7 of the file onnx/version_converter/adapters/upsample_6_7.h of the component Version Converter Adapters. The manipulation of the argument inputs leads to null pointer dereference. This vulnerability is documented as CVE-2026-44512. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in ONNX up to 1.21.0 and classified as problematic. This issue affects the function Upsample_6_7::adapt_upsample_6_7 of the file onnx/version_converter/adapters/upsample_6_7.h of the component Version Converter Adapters. The manipulation of the argument inputs with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Impacted is availability. The summary by CVE is:

Open Neural Network Exchange (ONNX) is an open standard for machine learning interoperability. From 1.9.0 before 1.22.0, onnx.version_converter.convert_version() can dereference a null pointer in Upsample_6_7::adapt_upsample_6_7() in onnx/version_converter/adapters/upsample_6_7.h when processing an untrusted model with an Upsample node that has zero inputs, causing an unrecoverable denial of service. This issue is fixed in version 1.22.0.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-44512 since 05/06/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 326083 (Linux Distros Unpatched Vulnerability : CVE-2026-44512), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.22.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (326083). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

• ONNX

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9
• 1.10
• 1.11
• 1.12
• 1.13
• 1.14
• 1.15
• 1.16
• 1.17
• 1.18
• 1.19
• 1.20
• 1.21.0

Website

• Product: https://github.com/onnx/onnx/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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