{"id":"CVE-2026-11940","state":"PUBLISHED","title":"tarfile extraction filter bypass allows escaping the destination directory","description":"tarfile.extractall() with the 'data' or 'tar'\n filter could be bypassed by a crafted archive where a hardlink \nreferences a symlink stored at a deeper name than the hardlink itself.  \nThe extraction fallback validated the symlink at it's archived location \nbut recreated it at the hardlink's shallower\npath, letting a relative\n target the filter judged contained escape the destination directory.  \nThis allowed a malicious tar archive to create a symlink pointing \noutside the destination, enabling out-of-destination file reads or \nwrites. This was an incomplete fix of CVE-2025-4330.","publishedAt":"2026-06-23T16:04:17.321Z","updatedAt":"2026-08-13T00:28:51.345Z","severity":{"score":7.8,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N","source":"PSF"},"assigner":"PSF","products":["Python Software Foundation CPython"],"affected":[{"vendor":"Python Software Foundation","product":"CPython","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"3.10.21","versionType":"python"},{"version":"3.11.0","status":"affected","lessThan":"3.11.16","versionType":"python"},{"version":"3.12.0","status":"affected","lessThan":"3.12.14","versionType":"python"},{"version":"3.13.0","status":"affected","lessThan":"3.13.15","versionType":"python"},{"version":"3.14.0","status":"affected","lessThan":"3.14.7","versionType":"python"},{"version":"3.15.0a1","status":"affected","lessThan":"3.15.0b4","versionType":"python"}],"repo":"https://github.com/python/cpython"}],"references":["https://github.com/python/cpython/pull/151559","https://mail.python.org/archives/list/security-announce@python.org/thread/LD6QIISNQFQYOIEPJNEUIPV7S3V76FZH/","https://github.com/python/cpython/issues/151558","https://github.com/python/cpython/commit/27dd970bf6b17ebca7c8ed486a40ab043ed7af8f","https://github.com/python/cpython/commit/672825e2f36a57e173959b0d9d409d4560dab8df","https://github.com/python/cpython/commit/771d12dda5140313db0ac550292987975651bbde","https://github.com/python/cpython/commit/79c06bd5c6afa3c440d50faf7ee1b147c8832b4c","https://github.com/python/cpython/commit/be13e86f6b9788a6f4d0419dffef72cbae5865c9","https://github.com/python/cpython/commit/e5fdbd8d5aa923bd9111b112ea73bd6ec7c47877","https://github.com/python/cpython/commit/0f852b3f07dd8e71e40326a51c02afbf16a42cc5"],"weaknesses":["CWE-22","CWE-59"],"ingestedAt":"2026-10-29T20:10:52.580Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/11xxx/CVE-2026-11940.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-11940","state":"PUBLISHED","datePublished":"2026-06-23T16:04:17.321Z","dateUpdated":"2026-08-13T00:28:51.345Z","assignerShortName":"PSF","assignerOrgId":"28c92f92-d60d-412d-b760-e73465c3df22","dateReserved":"2026-06-10T19:50:59.923Z"},"containers":{"cna":{"title":"tarfile extraction filter bypass allows escaping the destination directory","descriptions":[{"lang":"en","value":"tarfile.extractall() with the 'data' or 'tar'\n filter could be bypassed by a crafted archive where a hardlink \nreferences a symlink stored at a deeper name than the hardlink itself.  \nThe extraction fallback validated the symlink at it's archived location \nbut recreated it at the hardlink's shallower\npath, letting a relative\n target the filter judged contained escape the destination directory.  \nThis allowed a malicious tar archive to create a symlink pointing \noutside the destination, enabling out-of-destination file reads or \nwrites. This was an incomplete fix of CVE-2025-4330."}],"affected":[{"vendor":"Python Software Foundation","product":"CPython","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"3.10.21","versionType":"python"},{"version":"3.11.0","status":"affected","lessThan":"3.11.16","versionType":"python"},{"version":"3.12.0","status":"affected","lessThan":"3.12.14","versionType":"python"},{"version":"3.13.0","status":"affected","lessThan":"3.13.15","versionType":"python"},{"version":"3.14.0","status":"affected","lessThan":"3.14.7","versionType":"python"},{"version":"3.15.0a1","status":"affected","lessThan":"3.15.0b4","versionType":"python"}],"repo":"https://github.com/python/cpython"}],"references":[{"url":"https://github.com/python/cpython/pull/151559","tags":["patch"]},{"url":"https://mail.python.org/archives/list/security-announce@python.org/thread/LD6QIISNQFQYOIEPJNEUIPV7S3V76FZH/","tags":["vendor-advisory"]},{"url":"https://github.com/python/cpython/issues/151558","tags":["issue-tracking"]},{"url":"https://github.com/python/cpython/commit/27dd970bf6b17ebca7c8ed486a40ab043ed7af8f","tags":["patch"]},{"url":"https://github.com/python/cpython/commit/672825e2f36a57e173959b0d9d409d4560dab8df","tags":["patch"]},{"url":"https://github.com/python/cpython/commit/771d12dda5140313db0ac550292987975651bbde","tags":["patch"]},{"url":"https://github.com/python/cpython/commit/79c06bd5c6afa3c440d50faf7ee1b147c8832b4c","tags":["patch"]},{"url":"https://github.com/python/cpython/commit/be13e86f6b9788a6f4d0419dffef72cbae5865c9","tags":["patch"]},{"url":"https://github.com/python/cpython/commit/e5fdbd8d5aa923bd9111b112ea73bd6ec7c47877","tags":["patch"]},{"url":"https://github.com/python/cpython/commit/0f852b3f07dd8e71e40326a51c02afbf16a42cc5","tags":["patch"]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":7.8,"baseSeverity":"HIGH","exploitMaturity":"NOT_DEFINED","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"HIGH","subIntegrityImpact":"HIGH","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-22","description":"CWE-22","lang":"en","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-59","description":"CWE-59","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"PSF","orgId":"28c92f92-d60d-412d-b760-e73465c3df22","dateUpdated":"2026-08-13T00:28:51.345Z"},"credits":[{"lang":"en","type":"reporter","value":"Haruki Oyama (https://github.com/harukioya)"},{"lang":"en","type":"coordinator","value":"Stan Ulbrych (https://github.com/StanFromIreland)"},{"lang":"en","type":"remediation reviewer","value":"Petr Viktorin (https://github.com/encukou)"}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-23T17:57:25.652265Z","id":"CVE-2026-11940","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":"2026-06-23T17:57:32.525Z"}}]}}}