{"id":"UBUNTU-CVE-2026-33748","details":"BuildKit is a toolkit for converting source code to build artifacts in an efficient, expressive and repeatable manner. Prior to version 0.28.1, insufficient validation of Git URL fragment subdir components may allow access to files outside the checked-out Git repository root. Possible access is limited to files on the same mounted filesystem. The issue has been fixed in version v0.28.1 The issue affects only builds that use Git URLs with a subpath component. As a workaround, avoid building Dockerfiles from untrusted sources or using the subdir component from an untrusted Git repository where the subdir component could point to a symlink.","modified":"2026-05-20T16:25:31.191955895Z","published":"2026-04-22T00:00:00Z","related":["USN-8230-1"],"upstream":["CVE-2026-33748"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-33748"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-33748"},{"type":"REPORT","url":"https://docs.docker.com/build/concepts/context/#url-fragments"},{"type":"REPORT","url":"https://github.com/moby/buildkit/releases/tag/v0.28.1"},{"type":"REPORT","url":"https://github.com/moby/buildkit/security/advisories/GHSA-4vrq-3vrq-g6gg"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8230-1"}],"affected":[{"package":{"name":"docker.io","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/docker.io?arch=source&distro=esm-infra%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.6.2~dfsg1-1ubuntu4","1.10.2-0ubuntu3","1.10.2-0ubuntu4","1.10.3-0ubuntu1","1.10.3-0ubuntu4","1.10.3-0ubuntu5","1.10.3-0ubuntu6","1.11.2-0ubuntu5~16.04","1.12.1-0ubuntu13~16.04.1","1.12.3-0ubuntu4~16.04.2","1.12.6-0ubuntu1~16.04.1","1.13.1-0ubuntu1~16.04.2","17.03.2-0ubuntu2~16.04.1","18.06.1-0ubuntu1~16.04.2","18.06.1-0ubuntu1.2~16.04.1","18.09.2-0ubuntu1~16.04.1","18.09.5-0ubuntu1~16.04.2","18.09.7-0ubuntu1~16.04.1","18.09.7-0ubuntu1~16.04.4","18.09.7-0ubuntu1~16.04.5","18.09.7-0ubuntu1~16.04.6","18.09.7-0ubuntu1~16.04.7","18.09.7-0ubuntu1~16.04.9+esm1","18.09.7-0ubuntu1~16.04.9+esm2"],"ecosystem_specific":{"binaries":[{"binary_version":"18.09.7-0ubuntu1~16.04.9+esm2","binary_name":"docker.io"},{"binary_version":"18.09.7-0ubuntu1~16.04.9+esm2","binary_name":"golang-docker-dev"},{"binary_version":"18.09.7-0ubuntu1~16.04.9+esm2","binary_name":"golang-github-docker-docker-dev"},{"binary_name":"vim-syntax-docker","binary_version":"18.09.7-0ubuntu1~16.04.9+esm2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33748.json"}},{"package":{"name":"docker.io","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/docker.io?arch=source&distro=esm-apps%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.13.1-0ubuntu6","17.03.2-0ubuntu1","17.03.2-0ubuntu3","17.03.2-0ubuntu5","17.12.1-0ubuntu1","18.06.1-0ubuntu1~18.04.1","18.06.1-0ubuntu1.2~18.04.1","18.09.2-0ubuntu1~18.04.1","18.09.5-0ubuntu1~18.04.2","18.09.7-0ubuntu1~18.04.1","18.09.7-0ubuntu1~18.04.3","18.09.7-0ubuntu1~18.04.4","19.03.6-0ubuntu1~18.04.1","19.03.6-0ubuntu1~18.04.2","19.03.6-0ubuntu1~18.04.3","20.10.2-0ubuntu1~18.04.2","20.10.2-0ubuntu1~18.04.3","20.10.7-0ubuntu1~18.04.1","20.10.7-0ubuntu1~18.04.2","20.10.7-0ubuntu5~18.04.2","20.10.7-0ubuntu5~18.04.3","20.10.12-0ubuntu2~18.04.1","20.10.21-0ubuntu1~18.04.2","20.10.21-0ubuntu1~18.04.3","20.10.21-0ubuntu1~18.04.3+esm1","20.10.21-0ubuntu1~18.04.3+esm2","20.10.21-0ubuntu1~18.04.3+esm3"],"ecosystem_specific":{"binaries":[{"binary_version":"20.10.21-0ubuntu1~18.04.3+esm3","binary_name":"docker.io"},{"binary_version":"20.10.21-0ubuntu1~18.04.3+esm3","binary_name":"golang-docker-dev"},{"binary_name":"golang-github-docker-docker-dev","binary_version":"20.10.21-0ubuntu1~18.04.3+esm3"},{"binary_version":"20.10.21-0ubuntu1~18.04.3+esm3","binary_name":"vim-syntax-docker"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33748.json"}},{"package":{"name":"docker.io","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/docker.io?arch=source&distro=esm-apps%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["19.03.2-0ubuntu1","19.03.6-0ubuntu1","19.03.8-0ubuntu1","19.03.8-0ubuntu1.20.04","19.03.8-0ubuntu1.20.04.1","19.03.8-0ubuntu1.20.04.2","20.10.2-0ubuntu1~20.04.2","20.10.2-0ubuntu1~20.04.3","20.10.7-0ubuntu1~20.04.1","20.10.7-0ubuntu1~20.04.2","20.10.7-0ubuntu5~20.04.1","20.10.7-0ubuntu5~20.04.2","20.10.12-0ubuntu2~20.04.1","20.10.21-0ubuntu1~20.04.1","20.10.21-0ubuntu1~20.04.2","20.10.21-0ubuntu1~20.04.4","20.10.21-0ubuntu1~20.04.5","20.10.21-0ubuntu1~20.04.6","20.10.21-0ubuntu1~20.04.6+esm1","20.10.21-0ubuntu1~20.04.6+esm2"],"ecosystem_specific":{"binaries":[{"binary_version":"20.10.21-0ubuntu1~20.04.6+esm2","binary_name":"golang-docker-dev"},{"binary_version":"20.10.21-0ubuntu1~20.04.6+esm2","binary_name":"golang-github-docker-docker-dev"},{"binary_name":"vim-syntax-docker","binary_version":"20.10.21-0ubuntu1~20.04.6+esm2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33748.json"}},{"package":{"name":"docker.io-app","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/docker.io-app?arch=source&distro=esm-apps%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"26.1.3-0ubuntu1~20.04.1+esm2"}]}],"versions":["20.10.25-0ubuntu1~20.04.1","20.10.25-0ubuntu1~20.04.2","24.0.5-0ubuntu1~20.04.1","24.0.7-0ubuntu2~20.04.1","26.1.3-0ub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with Ubuntu Pro: https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33748.json"}},{"package":{"name":"docker.io-app","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/docker.io-app?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"29.1.3-0ubuntu3~22.04.2"}]}],"versions":["20.10.25-0ubuntu1~22.04.1","20.10.25-0ubuntu1~22.04.2","24.0.5-0ubuntu1~22.04.1","24.0.7-0ubuntu2~22.04.1","26.1.3-0ubuntu1~22.04.1","27.5.1-0ubuntu3~22.04.1","27.5.1-0ubuntu3~22.04.2","28.2.2-0ubuntu1~22.04.1","29.1.3-0ubuntu3~22.04.1"],"ecosystem_specific":{"binaries":[{"binary_name":"docker.io","binary_version":"29.1.3-0ubuntu3~22.04.2"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33748.json"}},{"package":{"name":"docker.io","ecosystem":"Ubuntu:Pro:22.04:LTS","purl":"pkg:deb/ubuntu/docker.io?arch=source&distro=esm-apps%2Fjammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["20.10.7-0ubuntu5","20.10.7-0ubuntu7","20.10.12-0ubuntu1","20.10.12-0ubuntu2","20.10.12-0ubuntu3","20.10.12-0ubuntu3+gke1.24.1","20.10.12-0ubuntu4","20.10.21-0ubuntu1~22.04.2","20.10.21-0ubuntu1~22.04.3","20.10.21-0ubuntu1~22.04.5","20.10.21-0ubuntu1~22.04.6","20.10.21-0ubuntu1~22.04.7","20.10.21-0ubuntu1~22.04.7+esm1","20.10.21-0ubuntu1~22.04.7+esm2","20.10.21-0ubuntu1~22.04.8","20.10.21-0ubuntu1~22.04.8+esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"golang-docker-dev","binary_version":"20.10.21-0ubuntu1~22.04.8+esm1"},{"binary_version":"20.10.21-0ubuntu1~22.04.8+esm1","binary_name":"golang-github-docker-docker-dev"},{"binary_version":"20.10.21-0ubuntu1~22.04.8+esm1","binary_name":"vim-syntax-docker"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33748.json"}},{"package":{"name":"docker.io-app","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/docker.io-app?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"29.1.3-0ubuntu3~24.04.2"}]}],"versions":["24.0.5-0ubuntu1","24.0.7-0ubuntu1","24.0.7-0ubuntu2","24.0.7-0ubuntu3","24.0.7-0ubuntu4","24.0.7-0ubuntu4.1","26.1.3-0ubuntu1~24.04.1","27.5.1-0ubuntu3~24.04.1","27.5.1-0ubuntu3~24.04.2","28.2.2-0ubuntu1~24.04.1","29.1.3-0ubuntu3~24.04.1"],"ecosystem_specific":{"binaries":[{"binary_version":"29.1.3-0ubuntu3~24.04.2","binary_name":"docker.io"}],"availability":"No subscription 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