Medium severity · published Oct 26, 2026
CVE-2026-115921
ONNX: Null Pointer Dereference in ScanInferenceFunction Due to Missing Required Attribute
New
6.2
CVSS
0.1%
EPSS
No
On KEV
Description
Open Neural Network Exchange (ONNX) is an open standard for machine learning interoperability. From 1.4.0 until 1.22.0, ScanInferenceFunction, ScanInferenceFunction_opset8, and ScanInferenceFunction_opset9 do not safely validate the required num_scan_inputs attribute. A missing attribute is dereferenced as a null pointer, while a negative value is converted to size_t and can reach an exceptional oversized allocation path. An untrusted model can therefore terminate or disrupt shape inference, including a negative-value model that can pass onnx.checker.check_model(). This issue is fixed in version 1.22.0.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 3% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
ON
onnx · onnx
>= 1.4.0, < 1.22.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-115921
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-115921
github.com
https://github.com/onnx/onnx/commit/dd6bc92ea39fd2274fd671f0734b0b8b558356f5
github.com
https://github.com/onnx/onnx/pull/7916
github.com
https://github.com/onnx/onnx/releases/tag/v1.22.0
github.com
https://github.com/onnx/onnx/security/advisories/GHSA-m4pr-6v3c-6fgr
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