Pillow: Heap over-read in WMF/EMF rendering via 16-bit dimension truncation (Windows builds)

{
  "id": "90af11547389b780cad5abca8e2c367b1ab4c3095996807787ca7884ec26b164",
  "url": "https://www.cve.org/CVERecord?id=CVE-2026-96644",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Pillow: Heap over-read in WMF/EMF rendering via 16-bit dimension truncation (Windows builds)",
    "summary": "Pillow is a Python imaging library. Prior to 13.0.0 on Windows, src/PIL/WmfImagePlugin.py passes unchecked 32-bit WMF or EMF dimensions to the native drawwmf handler in src/display.c. The handler sizes a DIB allocation from 16-bit-truncated bcWidth and bcHeight fields but copies pixel data using the original full dimensions. A crafted wide, short metafile can pass the pixel-count decompression-bomb check and make the Windows-only renderer read beyond the heap buffer, potentially disclosing memory or crashing the process. This issue is fixed in version 13.0.0.",
    "evidence": "cve:CVE-2026-96644",
    "products": [
      {
        "name": {
          "value": "Pillow",
          "evidence": "/containers/cna/affected/0/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-96644",
      "aliases": [
        "CVE-2026-96644"
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "version": "4.0",
            "baseScore": 7.1,
            "attackVector": "NETWORK",
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N",
            "userInteraction": "PASSIVE",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "privilegesRequired": "NONE",
            "subIntegrityImpact": "NONE",
            "vulnIntegrityImpact": "NONE",
            "subAvailabilityImpact": "NONE",
            "vulnAvailabilityImpact": "HIGH",
            "subConfidentialityImpact": "NONE",
            "vulnConfidentialityImpact": "LOW"
          }
        }
      ],
      "affected": [
        {
          "vendor": "python-pillow",
          "product": "Pillow",
          "versions": [
            {
              "status": "affected",
              "version": "< 13.0.0"
            }
          ]
        }
      ],
      "modified": "2026-10-28T18:22:38.027Z",
      "provider": "cve",
      "references": [
        "https://github.com/python-pillow/Pillow/security/advisories/GHSA-9v9v-9qvf-h2hj",
        "https://github.com/python-pillow/Pillow/pull/10120",
        "https://github.com/python-pillow/Pillow/commit/4cf46bee338304c5c8968fd7f132ba0d40c428b7",
        "https://github.com/python-pillow/Pillow/releases/tag/13.0.0"
      ],
      "provider_metadata": {
        "adp": [
          {
            "title": "CISA ADP Vulnrichment",
            "metrics": [
              {
                "other": {
                  "type": "ssvc",
                  "content": {
                    "id": "CVE-2026-96644",
                    "role": "CISA Coordinator",
                    "options": [
                      {
                        "Exploitation": "poc"
                      },
                      {
                        "Automatable": "no"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "version": "2.0.3",
                    "timestamp": "2026-10-28T18:22:22.322892Z"
                  }
                }
              }
            ],
            "references": [
              {
                "url": "https://github.com/python-pillow/Pillow/security/advisories/GHSA-9v9v-9qvf-h2hj",
                "tags": [
                  "exploit"
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            "providerMetadata": {
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              "shortName": "CISA-ADP",
              "dateUpdated": "2026-10-28T18:22:38.027Z"
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        ],
        "cna": {
          "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
          "shortName": "GitHub_M",
          "dateUpdated": "2026-10-21T20:54:43.537Z"
        }
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-96644",
        "evidence": "/cveMetadata/cveId"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/containers/cna/metrics"
  },
  "source_id": "core-cve",
  "document_id": 472583,
  "published_at": "2026-10-21T20:54:43.537+00:00"
}