CVE-2026-63632: onnx Out-of-bounds Read
Vulnerability summary
CVE-2026-63632 is a low (CVSS 3.3) Out-of-bounds Read vulnerability in onnx. EPSS estimates a 0.17% chance of exploitation in the next 30 days, higher than 5.6% of scored vulnerabilities.
Timeline
- 18-08-2026PublishedVulnerability first disclosed.
- 18-08-2026Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
5 scores · 5 sources · 1 version- OSV · PypiEcosystem advisory · calculated3.3LowCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
- OSV · UbuntuEcosystem advisory · calculated3.3LowCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
- OSV · DebianEcosystem advisory · calculated3.3LowCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
- NVDNIST3.3LowCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
EPSS trend
Probability
0.17%
Chance of exploitation in the next 30 days
Percentile
6%
Versus all other CVEs
30-day change
-0.06 pp
From 0.23% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Debian1 product
- onnxAll versions (No fix recorded)
Onnx1 product
- onnx≥ 1.3.0, < 1.22.0
PyPI1 product
- onnx≥ 1.3.0, < 1.22.0
Ubuntu1 product
- onnxAll versions (No fix recorded)
4 vendors · 4 products
References
11 links- github.com/onnx/onnxPACKAGE
- pypi.org/project/onnxPACKAGE
