Heap-based buffer overflow in onnx - #VU136855
Published: July 3, 2026
Vulnerability identifier: #VU136855
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: N/A
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Open Neural Network Exchange
Affected software:
onnx
onnx
Detailed vulnerability description
The vulnerability allows a remote attacker to disclose sensitive information or cause a denial of service.
The vulnerability exists due to a heap-based buffer overflow in Gemm_7_6::adapt_gemm_7_6() when processing a crafted model during version conversion. A remote attacker can trick the victim into processing a specially crafted model to disclose sensitive information or cause a denial of service.
User interaction is required to process the crafted model through onnx.version_converter.convert_version(model, 6) during opset downgrade from 7 to 6.
Remediation
Install security update from vendor's website.