CVE-2026-63632

ONNX: Heap-Buffer-Overflow READ in Gemm Version Converter Adapter via Undersized Input Shape

Published: Aug 18, 2026Updated: Sep 18, 2026 Sources: CVE List NVDCWE-125

3.3LOW

Description

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.

No summary for this CVE yet.

CVSS Vector Breakdown

Exploitability

AV:LAttack Vector

Local

AC:LAttack Complexity

Low

PR:NPrivileges Required

None

UI:RUser Interaction

Required

Scope

S:UScope

Unchanged

Impact

C:NConfidentiality

None

I:NIntegrity

None

A:LAvailability

Low

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Weaknesses

CWE-125

Affected Products

onnx

oss-projectaka onnx-mlir

onnxLibrary

AI / ML / ml-framework

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique

Collection

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References

https://github.com/onnx/onnx/commit/e9c74f596eaa0250f89e52a54160a25bbcb25b66

github.com

https://github.com/onnx/onnx/pull/7880

github.com

https://github.com/onnx/onnx/releases/tag/v1.22.0

github.com

and 1 more references View all →

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