CVE-2026-33748
BuildKit Git URL subdir component can cause access to restricted files
In short
BuildKit doesn't properly validate the subdir component in Git URLs, allowing attackers to access files outside the intended repository directory. This could expose sensitive files on the same filesystem during container builds.
Technical detail
Insufficient validation of Git URL fragment subdir components enables path traversal (CWE-22) and symlink following (CWE-59), allowing unauthorized file access beyond the repository root during build operations. The attack vector requires builds using Git URLs with subpath components; impact is limited to files on the same mounted filesystem.
Summary generated and translated by AI from the official description.
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.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Affected products
moby · buildkitWant to know if your infrastructure is exposed to this?
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