TI-2026-45276 Aliases CVE-2026-63632 GHSA-p893-rvq9-2xf9

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

MEDIUM 49CWE-125Published 2026-08-18 · Updated 2026-08-18

Key facts

Attack vector: Local
Privileges required: None
User interaction: Required
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: None · None · Low
Fix status: Partial Red Hat: 1 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00168 6th percentileScored 2026-11-07

Fix Partial onnx (onnx): 1.22.0onnx (PyPI): 1.22.0Red Hat: 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
onnx	onnx	1.3.0 to before 1.22.0	1.22.0	Patch available	CNA
—	onnx (PyPI)	1.3.0 to before 1.22.0	1.22.0	Patch available	GHSA-p893-rvq9-2xf9

onnx Vendoronnx Affected 1.3.0 to before 1.22.0 Fixed in 1.22.0 Patch available CNA
onnx (PyPI) Vendor— Affected 1.3.0 to before 1.22.0 Fixed in 1.22.0 Patch available GHSA-p893-rvq9-2xf9

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:a:linuxfoundation:onnx::::::::	—	—	backstage

cpe:2.3:a:linuxfoundation:onnx:*:*:*:*:*:*:*:* Versions — — ·backstage

Remediation

Fix · CNA onnx (onnx) Fixed in 1.22.0
Fix · GHSA-p893-rvq9-2xf9 onnx (PyPI) Fixed in 1.22.0 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Low. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat OpenShift AI (RHOAI)	Affected	No fix yet: Fix deferred

Not affected: 1 product

Red Hat OpenShift AI (RHOAI)

Timeline

2026-10-02 Threatist record created from CVE-2026-63632
2026-10-03 Alias added: GHSA-p893-rvq9-2xf9

References

Other 5

TI-2026-22763 ONNX Untrusted Model Repository Warnings Suppressed by silent=True in onnx.hub.load() — Silent Supply-Chain Attack CVSS 3.1CRITICAL 9.1
TI-2026-21896 ONNX: Path Traversal via Symlink CVSS 4.0HIGH 8.7
TI-2024-07209 Arbitrary File Overwrite in onnx/onnx CVSS 3.1CRITICAL 9.1
TI-2024-04814 Arbitrary File Overwrite in download_model_with_test_data in onnx/onnx CVSS 3.1HIGH 8.8
TI-2026-36338 ONNX symlink-following and path-traversal arbitrary file write CVSS 4.0MEDIUM 6.8
TI-2026-32442 ONNX: Null Pointer Dereference in Upsample Version Converter Adapter (Zero Inputs) CVSS 3.1MEDIUM 5.5

See all 16 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences