{"id":"CVE-2026-96642","state":"PUBLISHED","title":"Pillow: TarIO negative size field causes infinite CPU-spin loop","description":"Pillow is a Python imaging library. Prior to 13.0.0, the TarIO initializer in src/PIL/TarIO.py accepts a negative octal member size and computes a backward seek that returns to the same 512-byte header. When the requested member name does not match, the parser repeatedly reads that header, consumes a full CPU core, and never returns. TarIO is reached only when an application directly uses PIL.TarIO.TarIO rather than the default Image.open() path. This issue is fixed in version 13.0.0.","publishedAt":"2026-10-21T20:49:56.989Z","updatedAt":"2026-10-30T16:07:09.659Z","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-3j72-p6qg-6xp7","https://github.com/python-pillow/Pillow/pull/10012","https://github.com/python-pillow/Pillow/commit/19b695fdcc5eddc37374e2b1645fc4185edaf71d","https://github.com/python-pillow/Pillow/releases/tag/13.0.0"],"weaknesses":["CWE-835"],"ingestedAt":"2026-10-30T16:24:06.740Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/96xxx/CVE-2026-96642.json","commit":"52408409ce2a766d916f7a10c578d10655ec3113","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-96642","state":"PUBLISHED","datePublished":"2026-10-21T20:49:56.989Z","dateUpdated":"2026-10-30T16:07:09.659Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-09-23T14:35:50.130Z"},"containers":{"cna":{"title":"Pillow: TarIO negative size field causes infinite CPU-spin loop","descriptions":[{"lang":"en","value":"Pillow is a Python imaging library. Prior to 13.0.0, the TarIO initializer in src/PIL/TarIO.py accepts a negative octal member size and computes a backward seek that returns to the same 512-byte header. When the requested member name does not match, the parser repeatedly reads that header, consumes a full CPU core, and never returns. TarIO is reached only when an application directly uses PIL.TarIO.TarIO rather than the default Image.open() path. 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-3j72-p6qg-6xp7","name":"https://github.com/python-pillow/Pillow/security/advisories/GHSA-3j72-p6qg-6xp7","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/python-pillow/Pillow/pull/10012","name":"https://github.com/python-pillow/Pillow/pull/10012","tags":["x_refsource_MISC"]},{"url":"https://github.com/python-pillow/Pillow/commit/19b695fdcc5eddc37374e2b1645fc4185edaf71d","name":"https://github.com/python-pillow/Pillow/commit/19b695fdcc5eddc37374e2b1645fc4185edaf71d","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-835","lang":"en","description":"CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-21T20:49:56.989Z"},"source":{"advisory":"GHSA-3j72-p6qg-6xp7","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/python-pillow/Pillow/security/advisories/GHSA-3j72-p6qg-6xp7","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-30T16:07:02.731167Z","id":"CVE-2026-96642","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-30T16:07:09.659Z"}}]}}}