{"id":"CVE-2026-115922","state":"PUBLISHED","title":"ONNX: Denial of service via unchecked expansion of packed sub-byte tensors in ONNX Python APIs","description":"Open Neural Network Exchange (ONNX) is an open standard for machine learning interoperability. Prior to 1.22.0, _unpack_2bit() and _unpack_4bit() resize unpacked arrays according to attacker-controlled TensorProto.dims without verifying that raw_data or int32_data encodes the declared number of elements. Materializing an untrusted UINT2, INT2, UINT4, INT4, or FLOAT4E2M1 tensor through onnx.numpy_helper.to_array() or onnx.reference.ReferenceEvaluator can therefore expand a small packed payload into a disproportionately large allocation and exhaust memory. This issue is fixed in version 1.22.0.","publishedAt":"2026-10-26T17:31:03.716Z","updatedAt":"2026-10-30T17:40:32.752Z","severity":{"score":6.2,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["onnx onnx"],"affected":[{"vendor":"onnx","product":"onnx","versions":[{"version":"< 1.22.0","status":"affected"}]}],"references":["https://github.com/onnx/onnx/security/advisories/GHSA-q69g-f4f5-v8m7","https://github.com/onnx/onnx/pull/8033","https://github.com/onnx/onnx/pull/8038","https://github.com/onnx/onnx/pull/8066","https://github.com/onnx/onnx/commit/05c1bc3bceceb8d3cf11e9e7fc7f19f971c44988","https://github.com/onnx/onnx/commit/8de2cf6aa47928e6515ac6d9e1a8b4758886a7df","https://github.com/onnx/onnx/commit/dce5876d6cc6cc30157af7d26a752ef44976da8e","https://github.com/onnx/onnx/releases/tag/v1.22.0"],"weaknesses":["CWE-789"],"ingestedAt":"2026-10-30T17:48:06.262Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/115xxx/CVE-2026-115922.json","commit":"55f09f8d4e130b1cf040d6352985ad794c15871d","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-115922","state":"PUBLISHED","datePublished":"2026-10-26T17:31:03.716Z","dateUpdated":"2026-10-30T17:40:32.752Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-10-23T20:21:45.107Z"},"containers":{"cna":{"title":"ONNX: Denial of service via unchecked expansion of packed sub-byte tensors in ONNX Python APIs","descriptions":[{"lang":"en","value":"Open Neural Network Exchange (ONNX) is an open standard for machine learning interoperability. Prior to 1.22.0, _unpack_2bit() and _unpack_4bit() resize unpacked arrays according to attacker-controlled TensorProto.dims without verifying that raw_data or int32_data encodes the declared number of elements. Materializing an untrusted UINT2, INT2, UINT4, INT4, or FLOAT4E2M1 tensor through onnx.numpy_helper.to_array() or onnx.reference.ReferenceEvaluator can therefore expand a small packed payload into a disproportionately large allocation and exhaust memory. This issue is fixed in version 1.22.0."}],"affected":[{"vendor":"onnx","product":"onnx","versions":[{"version":"< 1.22.0","status":"affected"}]}],"references":[{"url":"https://github.com/onnx/onnx/security/advisories/GHSA-q69g-f4f5-v8m7","name":"https://github.com/onnx/onnx/security/advisories/GHSA-q69g-f4f5-v8m7","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/onnx/onnx/pull/8033","name":"https://github.com/onnx/onnx/pull/8033","tags":["x_refsource_MISC"]},{"url":"https://github.com/onnx/onnx/pull/8038","name":"https://github.com/onnx/onnx/pull/8038","tags":["x_refsource_MISC"]},{"url":"https://github.com/onnx/onnx/pull/8066","name":"https://github.com/onnx/onnx/pull/8066","tags":["x_refsource_MISC"]},{"url":"https://github.com/onnx/onnx/commit/05c1bc3bceceb8d3cf11e9e7fc7f19f971c44988","name":"https://github.com/onnx/onnx/commit/05c1bc3bceceb8d3cf11e9e7fc7f19f971c44988","tags":["x_refsource_MISC"]},{"url":"https://github.com/onnx/onnx/commit/8de2cf6aa47928e6515ac6d9e1a8b4758886a7df","name":"https://github.com/onnx/onnx/commit/8de2cf6aa47928e6515ac6d9e1a8b4758886a7df","tags":["x_refsource_MISC"]},{"url":"https://github.com/onnx/onnx/commit/dce5876d6cc6cc30157af7d26a752ef44976da8e","name":"https://github.com/onnx/onnx/commit/dce5876d6cc6cc30157af7d26a752ef44976da8e","tags":["x_refsource_MISC"]},{"url":"https://github.com/onnx/onnx/releases/tag/v1.22.0","name":"https://github.com/onnx/onnx/releases/tag/v1.22.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"LOCAL","availabilityImpact":"HIGH","baseScore":6.2,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-789","lang":"en","description":"CWE-789: Memory Allocation with Excessive Size Value","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-26T17:31:03.716Z"},"source":{"advisory":"GHSA-q69g-f4f5-v8m7","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-30T17:40:12.778537Z","id":"CVE-2026-115922","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-30T17:40:32.752Z"}}]}}}