CVE-2026-33748
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk41th percentile - higher than 41% of all known CVEs
Summary
BuildKit versions prior to 0.28.1 have insufficient validation of Git URL fragment subdir components, which may allow access to files outside the checked-out Git repository root. Access is limited to files on the same mounted filesystem.
Risk Assessment
An attacker may access files outside the repository when building from an untrusted source, potentially leading to data leakage. The vulnerability only affects builds using Git URLs with a subpath component.
Recommendation
Update BuildKit to version 0.28.1, which fixes the vulnerability. As a workaround, avoid building Dockerfiles from untrusted sources or using the subdir component from untrusted Git repositories.
Other vulnerabilities in BuildKit
See all- CVE-2026-93321Medium
A malicious frontend can submit an LLB definition that causes buildkitd to panic and terminate, interrupting all builds running on that daemon.
- CVE-2026-93315Medium
When proxy networking with CA injection is enabled, a build can modify its CA bundle before cleanup. This may cause cleanup to block, operate outside the build rootfs, or fail without failing the build.
- CVE-2026-97275Medium
Improper Validation of Specified Quantity in Input vulnerability in VillaTheme BuildKit – Product Builder for WooCommerce – Custom PC Builder woo-product-builder allows Input Data Manipulation.This issue affects BuildKit – Product Builder for WooCommerce – Custom PC Builder: from n/a through 1.0.28.
- CVE-2026-93323Medium
The Dockerfile frontend loaded Dockerfile and .dockerignore files into memory without a size limit. A build context with an oversized file could cause buildkitd to allocate memory proportional to the file size, potentially exhausting memory and terminating the daemon, interrupting other builds.
- CVE-2026-93322Medium
A malicious frontend can submit an LLB definition that causes buildkitd to panic and terminate, interrupting all builds running on that daemon.
- CVE-2026-93320Medium
BuildKit may be tricked into performing file actions with special file inodes where regular files are expected. Special files may block operations or, on rootful workers, allow unintended host device access.
- CVE-2026-93319Medium
A malicious external BuildKit frontend can send requests using the internal API that can create conditions for a data race that can cause the BuildKit daemon to panic.
- CVE-2026-93318High
A malicious image can advertise DiffIDs from another image while containing different layer contents. In affected versions, BuildKit could use the advertised DiffIDs to derive cache and snapshot identity without validating that they matched the actual layer contents. If a BuildKit daemon with shared or persistent cache first processes such a malicious image, a later build using the victim image may mount the attacker-controlled layer contents as the base image. This can allow code from the malicious image to run in the victim build, for example by replacing a commonly executed path such as /bin/sh. The attacker-controlled code may read build secrets mounted into the build, access other build resources, alter output artifacts, or hang the build. The issue affects both regular snapshotters and lazy-pulling snapshotters such as stargz.
- CVE-2026-93317Medium
An unauthenticated attacker controlling a registry or OCI-layout blob source could provide blob contents that did not match the claimed digest. The resulting snapshot could be cached under that digest and reused by a later victim build, compromising build-input integrity.
- CVE-2026-93316High
If BuildKit daemon is started with --cdi-disabled it can lead to daemon panic when builds try to use CDI devices. This can happen maliciously or by accident.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

