CVE-2026-96636 (GCVE-0-2026-96636)

Vulnerability from cvelistv5 – Published: 2026-10-21 21:05 – Updated: 2026-10-21 21:05
VLAI
Title
Pillow: Decompression-bomb protection bypass via multi-frame seek() in MPO and DCX (MpoImageFile.seek / DcxImageFile.seek)
Summary
Pillow is a Python imaging library. Prior to 13.0.0, MpoImageFile.seek() and DcxImageFile.seek() reparse later MPO or DCX frames and replace self._size without rerunning Image._decompression_bomb_check(). A crafted multi-frame image can use a tiny first frame to pass Image.open() and then declare an over-limit later frame. Normal frame iteration through seek(), load(), or ImageSequence.Iterator can decode that frame and commit hundreds of megabytes or more, causing memory-exhaustion denial of service. This issue is fixed in version 13.0.0.
Severity
6.5 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
CWE
  • CWE-400 - Uncontrolled Resource Consumption
  • CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7734 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
python-pillow Pillow Affected: < 13.0.0
guessed Create a notification for this product.
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "Pillow",
          "vendor": "python-pillow",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 13.0.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Pillow is a Python imaging library. Prior to 13.0.0, MpoImageFile.seek() and DcxImageFile.seek() reparse later MPO or DCX frames and replace self._size without rerunning Image._decompression_bomb_check(). A crafted multi-frame image can use a tiny first frame to pass Image.open() and then declare an over-limit later frame. Normal frame iteration through seek(), load(), or ImageSequence.Iterator can decode that frame and commit hundreds of megabytes or more, causing memory-exhaustion denial of service. This issue is fixed in version 13.0.0."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-400",
              "description": "CWE-400: Uncontrolled Resource Consumption",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-409",
              "description": "CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-21T21:05:20.850Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/python-pillow/Pillow/security/advisories/GHSA-p8hx-v2p6-rp84",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/python-pillow/Pillow/security/advisories/GHSA-p8hx-v2p6-rp84"
        },
        {
          "name": "https://github.com/python-pillow/Pillow/pull/10011",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/python-pillow/Pillow/pull/10011"
        },
        {
          "name": "https://github.com/python-pillow/Pillow/commit/f1acfc54c53502948d0d14121872061df931db48",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/python-pillow/Pillow/commit/f1acfc54c53502948d0d14121872061df931db48"
        },
        {
          "name": "https://github.com/python-pillow/Pillow/releases/tag/13.0.0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/python-pillow/Pillow/releases/tag/13.0.0"
        }
      ],
      "source": {
        "advisory": "GHSA-p8hx-v2p6-rp84",
        "discovery": "UNKNOWN"
      },
      "title": "Pillow: Decompression-bomb protection bypass via multi-frame seek() in MPO and DCX (MpoImageFile.seek / DcxImageFile.seek)"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-96636",
    "datePublished": "2026-10-21T21:05:20.850Z",
    "dateReserved": "2026-09-23T14:35:50.130Z",
    "dateUpdated": "2026-10-21T21:05:20.850Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-96636",
      "date": "2026-10-23",
      "epss": "0.0028",
      "percentile": "0.19461"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "Pillow",
                "vendor": "python-pillow",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003c 13.0.0"
                  }
                ]
              }
            ],
            "source": "security-advisories@github.com"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "Pillow is a Python imaging library. Prior to 13.0.0, MpoImageFile.seek() and DcxImageFile.seek() reparse later MPO or DCX frames and replace self._size without rerunning Image._decompression_bomb_check(). A crafted multi-frame image can use a tiny first frame to pass Image.open() and then declare an over-limit later frame. Normal frame iteration through seek(), load(), or ImageSequence.Iterator can decode that frame and commit hundreds of megabytes or more, causing memory-exhaustion denial of service. This issue is fixed in version 13.0.0."
          }
        ],
        "id": "CVE-2026-96636",
        "lastModified": "2026-10-22T16:46:48.920",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 6.5,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "REQUIRED",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 2.8,
              "impactScore": 3.6,
              "source": "security-advisories@github.com",
              "type": "Secondary"
            }
          ]
        },
        "published": "2026-10-21T21:20:31.760",
        "references": [
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/python-pillow/Pillow/commit/f1acfc54c53502948d0d14121872061df931db48"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/python-pillow/Pillow/pull/10011"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/python-pillow/Pillow/releases/tag/13.0.0"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/python-pillow/Pillow/security/advisories/GHSA-p8hx-v2p6-rp84"
          }
        ],
        "sourceIdentifier": "security-advisories@github.com",
        "vulnStatus": "Undergoing Analysis",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-400"
              },
              {
                "lang": "en",
                "value": "CWE-409"
              }
            ],
            "source": "security-advisories@github.com",
            "type": "Primary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-10-22T00:50:10+00:00",
      "cve": "CVE-2026-96636",
      "id": "CVE-2026-96636",
      "initial_release_date": "2026-10-21T21:05:20.850000+00:00",
      "product_status:known_affected": "94",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "pillow: pillow: Denial of Service via decompression bomb check bypass in multi-frame images",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-96636.json",
      "version": "3"
    }
  }
}



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