{"id":"CVE-2026-96637","state":"PUBLISHED","title":"Pillow: Decompression bomb check bypass in SpiderImagePlugin.seek() leads to unbounded allocation DoS","description":"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.","publishedAt":"2026-10-21T21:01:20.249Z","updatedAt":"2026-10-23T21:18:59.858Z","severity":{"score":7.1,"label":"High","version":"4.0","vector":"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","source":"GitHub_M"},"assigner":"GitHub_M","products":["python-pillow Pillow"],"affected":[{"vendor":"python-pillow","product":"Pillow","versions":[{"version":"< 13.0.0","status":"affected"}]}],"references":["https://github.com/python-pillow/Pillow/security/advisories/GHSA-g842-9rc4-69pw","https://github.com/python-pillow/Pillow/pull/10076","https://github.com/python-pillow/Pillow/commit/7cb0e02389d8aac2a60896a490f572db0b07b841","https://github.com/python-pillow/Pillow/releases/tag/13.0.0"],"weaknesses":["CWE-400","CWE-409"],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/96xxx/CVE-2026-96637.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-96637","state":"PUBLISHED","datePublished":"2026-10-21T21:01:20.249Z","dateUpdated":"2026-10-23T21:18:59.858Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-09-23T14:35:50.130Z"},"containers":{"cna":{"title":"Pillow: Decompression bomb check bypass in SpiderImagePlugin.seek() leads to unbounded allocation DoS","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."}],"affected":[{"vendor":"python-pillow","product":"Pillow","versions":[{"version":"< 13.0.0","status":"affected"}]}],"references":[{"url":"https://github.com/python-pillow/Pillow/security/advisories/GHSA-g842-9rc4-69pw","name":"https://github.com/python-pillow/Pillow/security/advisories/GHSA-g842-9rc4-69pw","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/python-pillow/Pillow/pull/10076","name":"https://github.com/python-pillow/Pillow/pull/10076","tags":["x_refsource_MISC"]},{"url":"https://github.com/python-pillow/Pillow/commit/7cb0e02389d8aac2a60896a490f572db0b07b841","name":"https://github.com/python-pillow/Pillow/commit/7cb0e02389d8aac2a60896a490f572db0b07b841","tags":["x_refsource_MISC"]},{"url":"https://github.com/python-pillow/Pillow/releases/tag/13.0.0","name":"https://github.com/python-pillow/Pillow/releases/tag/13.0.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":7.1,"baseSeverity":"HIGH","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"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-400","lang":"en","description":"CWE-400: Uncontrolled Resource Consumption","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-409","lang":"en","description":"CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-21T21:01:20.249Z"},"source":{"advisory":"GHSA-g842-9rc4-69pw","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-23T17:32:50.503938Z","id":"CVE-2026-96637","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-23T21:18:59.858Z"}}]}}}