{"id":"CVE-2026-66484","state":"PUBLISHED","title":"Path Traversal in GNU cpio","description":"GNU cpio contains a Path Traversal vulnerability in its tar archive extraction functionality. When extracting a tar archive in copy-in mode with the --no-absolute-filenames option, the extracted file name is normalized but the tar hard-link target is passed to the link_to_name function without equivalent sanitization before calling link function. A tar archive provided by an attacker, containing a hard-link entry whose linkname is set to an absolute path outside the extraction directory, can cause cpio to create a hard link to an existing file outside the intended extraction directory, breaking the expected guarantee of --no-absolute-filenames and allowing archive-controlled linkage to external files.\n\nThis issue has been fixed in commit e2b9cbdd3354d2b1569b7390d1bc15c1930559ad","publishedAt":"2026-08-10T10:25:27.901Z","updatedAt":"2026-08-10T10:57:14.423Z","severity":{"score":4.6,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N","source":"CERT-PL"},"assigner":"CERT-PL","products":["GNU cpio"],"affected":[{"vendor":"GNU","product":"cpio","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"2.15","versionType":"custom"}],"repo":"https://git.savannah.gnu.org/cgit/cpio.git","programFiles":["tar.c"]}],"references":["https://cert.pl/en/posts/2026/08/CVE-2026-66484","https://git.savannah.gnu.org/cgit/cpio.git"],"weaknesses":["CWE-22"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/66xxx/CVE-2026-66484.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-66484","state":"PUBLISHED","datePublished":"2026-08-10T10:25:27.901Z","dateUpdated":"2026-08-10T10:57:14.423Z","assignerShortName":"CERT-PL","assignerOrgId":"4bb8329e-dd38-46c1-aafb-9bf32bcb93c6","dateReserved":"2026-07-27T11:32:08.682Z"},"containers":{"cna":{"title":"Path Traversal in GNU cpio","descriptions":[{"lang":"en","value":"GNU cpio contains a Path Traversal vulnerability in its tar archive extraction functionality. When extracting a tar archive in copy-in mode with the --no-absolute-filenames option, the extracted file name is normalized but the tar hard-link target is passed to the link_to_name function without equivalent sanitization before calling link function. A tar archive provided by an attacker, containing a hard-link entry whose linkname is set to an absolute path outside the extraction directory, can cause cpio to create a hard link to an existing file outside the intended extraction directory, breaking the expected guarantee of --no-absolute-filenames and allowing archive-controlled linkage to external files.\n\nThis issue has been fixed in commit e2b9cbdd3354d2b1569b7390d1bc15c1930559ad"}],"affected":[{"vendor":"GNU","product":"cpio","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"2.15","versionType":"custom"}],"repo":"https://git.savannah.gnu.org/cgit/cpio.git","programFiles":["tar.c"]}],"references":[{"url":"https://cert.pl/en/posts/2026/08/CVE-2026-66484","tags":["third-party-advisory"]},{"url":"https://git.savannah.gnu.org/cgit/cpio.git","tags":["product"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"LOCAL","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"ACTIVE","vulnConfidentialityImpact":"NONE","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"LOW","subIntegrityImpact":"LOW","vulnAvailabilityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"MEDIUM","baseScore":4.6,"vectorString":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-22","lang":"en","description":"CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')","type":"CWE"}]}],"providerMetadata":{"shortName":"CERT-PL","orgId":"4bb8329e-dd38-46c1-aafb-9bf32bcb93c6","dateUpdated":"2026-08-10T10:25:27.901Z"},"cpeApplicability":[{"operator":"OR","nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:gnu:cpio:*:*:*:*:*:*:*:*","versionStartIncluding":"0","versionEndIncluding":"2.15"}]}]}],"tags":["x_open-source"],"credits":[{"lang":"en","value":"Michał Majchrowicz (AFINE Team)","type":"finder"},{"lang":"en","value":"Marcin Wyczechowski (AFINE Team)","type":"finder"}],"source":{"discovery":"EXTERNAL"},"x_generator":{"engine":"Vulnogram 1.0.3"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-10T10:57:05.821880Z","id":"CVE-2026-66484","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-10T10:57:14.423Z"}}]}}}