CVE-2026-115922

MEDIUM 6.2

ONNX: Denial of service via unchecked expansion of packed sub-byte tensors in ONNX Python APIs

CVSS Score

6.2

EPSS Score

0.0%

EPSS Percentile

0th

Open Neural Network Exchange (ONNX) is an open standard for machine learning interoperability. Prior to 1.22.0, _unpack_2bit() and _unpack_4bit() resize unpacked arrays according to attacker-controlled TensorProto.dims without verifying that raw_data or int32_data encodes the declared number of elements. Materializing an untrusted UINT2, INT2, UINT4, INT4, or FLOAT4E2M1 tensor through onnx.numpy_helper.to_array() or onnx.reference.ReferenceEvaluator can therefore expand a small packed payload into a disproportionately large allocation and exhaust memory. This issue is fixed in version 1.22.0.

CWE	CWE-789
Vendor	onnx
Product	onnx
Published	Oct 26, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Affected Versions

onnx / onnx

< 1.22.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/onnx/onnx/security/advisories/GHSA-q69g-f4f5-v8m7 github.com: https://github.com/onnx/onnx/pull/8033 github.com: https://github.com/onnx/onnx/pull/8038 github.com: https://github.com/onnx/onnx/pull/8066 github.com: https://github.com/onnx/onnx/commit/05c1bc3bceceb8d3cf11e9e7fc7f19f971c44988 github.com: https://github.com/onnx/onnx/commit/8de2cf6aa47928e6515ac6d9e1a8b4758886a7df github.com: https://github.com/onnx/onnx/commit/dce5876d6cc6cc30157af7d26a752ef44976da8e github.com: https://github.com/onnx/onnx/releases/tag/v1.22.0