CVE-2026-96637 (GCVE-0-2026-96637)

Vulnerability from cvelistv5 – Published: 2026-10-21 21:01 – Updated: 2026-10-21 21:01
VLAI
Title
Pillow: Decompression bomb check bypass in SpiderImagePlugin.seek() leads to unbounded allocation DoS
Summary
Pillow is a Python imaging library. Prior to 13.0.0, SpiderImageFile.seek() in src/PIL/SpiderImagePlugin.py reparses a later SPIDER stack frame and replaces self._size without rerunning Image._decompression_bomb_check(). A tiny file can use a safe first frame to pass Image.open() and then declare very large dimensions in a later mode F frame. Loading that frame allocates approximately four bytes per attacker-declared pixel and can consume multiple gigabytes of memory. This issue is fixed in version 13.0.0.
Severity
7.1 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
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.
Show details on NVD website
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "Pillow",
          "vendor": "python-pillow",
          "versions": [
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              "version": "\u003c 13.0.0"
            }
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          "value": "Pillow is a Python imaging library. Prior to 13.0.0, SpiderImageFile.seek() in src/PIL/SpiderImagePlugin.py reparses a later SPIDER stack frame and replaces self._size without rerunning Image._decompression_bomb_check(). A tiny file can use a safe first frame to pass Image.open() and then declare very large dimensions in a later mode F frame. Loading that frame allocates approximately four bytes per attacker-declared pixel and can consume multiple gigabytes of memory. This issue is fixed in version 13.0.0."
        }
      ],
      "metrics": [
        {
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            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
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          "descriptions": [
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              "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": "2026-10-21T21:01:20.249Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/python-pillow/Pillow/security/advisories/GHSA-g842-9rc4-69pw",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/python-pillow/Pillow/security/advisories/GHSA-g842-9rc4-69pw"
        },
        {
          "name": "https://github.com/python-pillow/Pillow/pull/10076",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/python-pillow/Pillow/pull/10076"
        },
        {
          "name": "https://github.com/python-pillow/Pillow/commit/7cb0e02389d8aac2a60896a490f572db0b07b841",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/python-pillow/Pillow/commit/7cb0e02389d8aac2a60896a490f572db0b07b841"
        },
        {
          "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-g842-9rc4-69pw",
        "discovery": "UNKNOWN"
      },
      "title": "Pillow: Decompression bomb check bypass in SpiderImagePlugin.seek() leads to unbounded allocation DoS"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-96637",
    "datePublished": "2026-10-21T21:01:20.249Z",
    "dateReserved": "2026-09-23T14:35:50.130Z",
    "dateUpdated": "2026-10-21T21:01:20.249Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
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      "date": "2026-10-23",
      "epss": "0.00333",
      "percentile": "0.25364"
    },
    "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, SpiderImageFile.seek() in src/PIL/SpiderImagePlugin.py reparses a later SPIDER stack frame and replaces self._size without rerunning Image._decompression_bomb_check(). A tiny file can use a safe first frame to pass Image.open() and then declare very large dimensions in a later mode F frame. Loading that frame allocates approximately four bytes per attacker-declared pixel and can consume multiple gigabytes of memory. This issue is fixed in version 13.0.0."
          }
        ],
        "id": "CVE-2026-96637",
        "lastModified": "2026-10-22T16:46:48.920",
        "metrics": {
          "cvssMetricV40": [
            {
              "cvssData": {
                "Automatable": "NOT_DEFINED",
                "Recovery": "NOT_DEFINED",
                "Safety": "NOT_DEFINED",
                "attackComplexity": "LOW",
                "attackRequirements": "NONE",
                "attackVector": "NETWORK",
                "availabilityRequirement": "NOT_DEFINED",
                "baseScore": 7.1,
                "baseSeverity": "HIGH",
                "confidentialityRequirement": "NOT_DEFINED",
                "exploitMaturity": "NOT_DEFINED",
                "integrityRequirement": "NOT_DEFINED",
                "modifiedAttackComplexity": "NOT_DEFINED",
                "modifiedAttackRequirements": "NOT_DEFINED",
                "modifiedAttackVector": "NOT_DEFINED",
                "modifiedPrivilegesRequired": "NOT_DEFINED",
                "modifiedSubAvailabilityImpact": "NOT_DEFINED",
                "modifiedSubConfidentialityImpact": "NOT_DEFINED",
                "modifiedSubIntegrityImpact": "NOT_DEFINED",
                "modifiedUserInteraction": "NOT_DEFINED",
                "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
                "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
                "modifiedVulnIntegrityImpact": "NOT_DEFINED",
                "privilegesRequired": "NONE",
                "providerUrgency": "NOT_DEFINED",
                "subAvailabilityImpact": "NONE",
                "subConfidentialityImpact": "NONE",
                "subIntegrityImpact": "NONE",
                "userInteraction": "PASSIVE",
                "valueDensity": "NOT_DEFINED",
                "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
                "version": "4.0",
                "vulnAvailabilityImpact": "HIGH",
                "vulnConfidentialityImpact": "NONE",
                "vulnIntegrityImpact": "NONE",
                "vulnerabilityResponseEffort": "NOT_DEFINED"
              },
              "source": "security-advisories@github.com",
              "type": "Secondary"
            }
          ]
        },
        "published": "2026-10-21T21:20:31.927",
        "references": [
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            "source": "security-advisories@github.com",
            "url": "https://github.com/python-pillow/Pillow/commit/7cb0e02389d8aac2a60896a490f572db0b07b841"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/python-pillow/Pillow/pull/10076"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/python-pillow/Pillow/releases/tag/13.0.0"
          },
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            "source": "security-advisories@github.com",
            "url": "https://github.com/python-pillow/Pillow/security/advisories/GHSA-g842-9rc4-69pw"
          }
        ],
        "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": "2026-10-22T00:50:12+00:00",
      "cve": "CVE-2026-96637",
      "id": "CVE-2026-96637",
      "initial_release_date": "2026-10-21T21:01:20.249000+00:00",
      "product_status:known_affected": "94",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "pillow: pillow: Denial of Service via decompression bomb bypass in SPIDER images",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-96637.json",
      "version": "3"
    }
  }
}



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