CVE-2026-63632: Onnx

Low severity, CVSS 3.3. EPSS: 0.2% chance of exploitation in the next 30 days.

Open Neural Network Exchange (ONNX) is an open standard for machine learning interoperability. From 1.3.0 until 1.22.0, onnx.version_converter.convert_version() can perform an out-of-bounds read in Gemm_7_6::adapt_gemm_7_6() in onnx/version_converter/adapters/gemm_7_6.h when a Gemm node has input tensors with fewer than two dimensions because B_shape[1], A_shape[0], or A_shape[1] is accessed without a rank check, potentially causing a process crash during an opset 7 to 6 downgrade. This issue is fixed in version 1.22.0.

Affected products

• Onnx Onnx: from 1.3.0, before 1.22.0 (fixed in 1.22.0)

Published 2026-08-18. Last modified 2026-09-18.