CVE-2026-44512 ONNX: Null Pointer Dereference in Upsample Version Converter Adapter (Zero Inputs)
An attacker can cause a denial of service by providing a malicious ONNX model with zero inputs to the version converter.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-44512?
CVE-2026-44512 is a medium-severity vulnerability in onnx, published on 8 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-476
Which versions are affected by CVE-2026-44512?
3 open source packages ship an affected version, including onnx. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
onnx PyPI | From 1.9.0 | 1.22.0 |
onnx PyPI | From 1.9.0 | 1.22.0 |
onnx PyPI | From 1.9.0 | 1.22.0 |
Products include Linuxfoundation Onnx.
How do I fix CVE-2026-44512?
Upgrade onnx to 1.22.0 or later.
Is CVE-2026-44512 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-44512 exists.
Other vulnerabilities in onnx
- CVE-2025-51480 Path traversal in n/a
- CVE-2024-5187 Arbitrary File Overwrite in download_model_with_test_data in onnx/onnx
- CVE-2026-27489 ONNX: Path Traversal via Symlink
- CVE-2026-34445 ONNX: Malicious ONNX models can crash servers by exploiting unprotected object settings.
- CVE-2026-28500 ONNX Untrusted Model Repository Warnings Suppressed by silent=True in onnx.hub.load() — Silent Supply-Chain Attack
Sources
Also known as DEBIAN-CVE-2026-44512, ECHO-584a-b2f6-d7a8, GHSA-hwpq-hmq9-wj77, PYSEC-2026-2689, UBUNTU-CVE-2026-44512.