{"id":"CVE-2026-63632","aliases":["GHSA-p893-rvq9-2xf9","PYSEC-2026-3587"],"url":"https://o3.security/vulnerability/CVE-2026-63632","summary":"ONNX: Heap-Buffer-Overflow READ in Gemm Version Converter Adapter via Undersized Input Shape","details":"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.","published":"2026-08-18T14:55:15.923Z","modified":"2026-08-20T10:17:20.536696Z","cvss":{"score":3.3,"severity":"LOW","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L"},"epss":{"score":0.00163,"percentile":0.058,"asOf":"2026-09-07"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"onnx","fixedVersion":"1.22.0"}],"fix":{"url":"https://github.com/onnx/onnx/commit/e9c74f596eaa0250f89e52a54160a25bbcb25b66","label":"onnx/onnx@e9c74f5"},"references":[{"type":"WEB","url":"https://github.com/onnx/onnx/releases/tag/v1.22.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63632.json"},{"type":"ADVISORY","url":"https://github.com/onnx/onnx/security/advisories/GHSA-p893-rvq9-2xf9"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63632"},{"type":"FIX","url":"https://github.com/onnx/onnx/commit/e9c74f596eaa0250f89e52a54160a25bbcb25b66"},{"type":"FIX","url":"https://github.com/onnx/onnx/pull/7880"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-20T10:17:20.536696Z"}}