Uncontrolled Memory Allocation in onnx - CVE-2026-115922
Published: November 10, 2026
Vulnerability identifier: #VU164360
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-115922
CWE-ID: CWE-789
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to exhaust available memory and cause a denial of service.
The vulnerability exists due to excessive memory allocation in ONNX's _unpack_2bit() and _unpack_4bit() helpers when materializing packed sub-byte tensors without verifying that their payloads contain enough elements for the declared dimensions. A remote attacker can supply a small model with oversized tensor dimensions and undersized raw_data or packed int32_data payloads to trigger excessive allocations through onnx.numpy_helper.to_array() or onnx.reference.ReferenceEvaluator and cause a denial of service.
Affected software
onnx
How to mitigate CVE-2026-115922
Install security update from vendor's website.
onnx - update to 1.22.0