{"id":"UBUNTU-CVE-2026-66484","details":"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. This issue has been fixed in commit e2b9cbdd3354d2b1569b7390d1bc15c1930559ad","modified":"2026-09-01T15:47:52.257087404Z","published":"2026-08-10T11:17:00Z","related":["USN-8704-1"],"upstream":["CVE-2026-66484"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-66484"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-66484"},{"type":"REPORT","url":"https://cert.pl/en/posts/2026/08/CVE-2026-66484"},{"type":"REPORT","url":"https://git.savannah.gnu.org/cgit/cpio.git"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8704-1"}],"affected":[{"package":{"name":"cpio","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/cpio?arch=source&distro=esm-infra-legacy%2Ftrusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.11+dfsg-1ubuntu1.2+esm3"}]}],"versions":["2.11+dfsg-1ubuntu1","2.11+dfsg-1ubuntu1.1","2.11+dfsg-1ubuntu1.2","2.11+dfsg-1ubuntu1.2+esm1","2.11+dfsg-1ubuntu1.2+esm2"],"ecosystem_specific":{"binaries":[{"binary_name":"cpio","binary_version":"2.11+dfsg-1ubuntu1.2+esm3"}],"availability":"Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-66484.json"}},{"package":{"name":"cpio","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/cpio?arch=source&distro=esm-infra-legacy%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.11+dfsg-5ubuntu1.1+esm2"}]}],"versions":["2.11+dfsg-4.1ubuntu1","2.11+dfsg-5ubuntu1","2.11+dfsg-5ubuntu1.1","2.11+dfsg-5ubuntu1.1+esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"cpio","binary_version":"2.11+dfsg-5ubuntu1.1+esm2"}],"availability":"Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-66484.json"}},{"package":{"name":"cpio","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/cpio?arch=source&distro=esm-infra%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.12+dfsg-6ubuntu0.18.04.4+esm1"}]}],"versions":["2.11+dfsg-6","2.12+dfsg-6","2.12+dfsg-6ubuntu0.18.04.1","2.12+dfsg-6ubuntu0.18.04.4"],"ecosystem_specific":{"binaries":[{"binary_name":"cpio","binary_version":"2.12+dfsg-6ubuntu0.18.04.4+esm1"},{"binary_name":"cpio-win32","binary_version":"2.12+dfsg-6ubuntu0.18.04.4+esm1"}],"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-66484.json"}},{"package":{"name":"cpio","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/cpio?arch=source&distro=esm-infra%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.13+dfsg-2ubuntu0.4+esm1"}]}],"versions":["2.12+dfsg-9","2.12+dfsg-9ubuntu1","2.13+dfsg-1","2.13+dfsg-2","2.13+dfsg-2ubuntu0.3","2.13+dfsg-2ubuntu0.4"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro","binaries":[{"binary_name":"cpio","binary_version":"2.13+dfsg-2ubuntu0.4+esm1"},{"binary_name":"cpio-win32","binary_version":"2.13+dfsg-2ubuntu0.4+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-66484.json"}},{"package":{"name":"cpio","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/cpio?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.13+dfsg-7ubuntu0.2"}]}],"versions":["2.13+dfsg-4ubuntu4","2.13+dfsg-7","2.13+dfsg-7ubuntu0.1"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"cpio","binary_version":"2.13+dfsg-7ubuntu0.2"},{"binary_name":"cpio-win32","binary_version":"2.13+dfsg-7ubuntu0.2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-66484.json"}},{"package":{"name":"cpio","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/cpio?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.15+dfsg-1ubuntu2.1"}]}],"versions":["2.13+dfsg-7.1","2.14+dfsg-1","2.15+dfsg-1","2.15+dfsg-1ubuntu1","2.15+dfsg-1ubuntu2"],"ecosystem_specific":{"binaries":[{"binary_name":"cpio","binary_version":"2.15+dfsg-1ubuntu2.1"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-66484.json"}},{"package":{"name":"cpio","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/cpio?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.15+dfsg-2.1ubuntu0.1"}]}],"versions":["2.15+dfsg-2ubuntu1","2.15+dfsg-2.1"],"ecosystem_specific":{"binaries":[{"binary_name":"cpio","binary_version":"2.15+dfsg-2.1ubuntu0.1"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-66484.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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"},{"type":"Ubuntu","score":"medium"}]}