BuildKit Git URL subdir component can cause access to restricted files

高 7.5CVE-2026-33748 · GHSA-4vrq-3vrq-g6gg · GO-2026-4859 · 27/03/2026 公開 · 26/10/2026 更新

要点

CVE-2026-33748 は github.com/moby/buildkit, buildkit (mobyproject) に影響する深刻度「高」 (CVSS 7.5) の脆弱性です。
今後30日間に悪用される確率（EPSS）：0.48%（全脆弱性の 41.5% より高い）。
対処：0.28.1 以降に更新してください。

パッケージ	影響を受けるバージョン	修正済みバージョン
github.com/moby/buildkit Go	`< 0.28.1`	`0.28.1`
buildkit mobyproject	`< 0.28.1`	`0.28.1`

概要

Impact

Insufficient validation of Git URL fragment subdir components (<url>#<ref>:<subdir>, docs) may allow access to files outside the checked-out Git repository root. Possible access is limited to files on the same mounted filesystem.

Patches

The issue has been fixed in version v0.28.1

Workarounds

The issue affects only builds that use Git URLs with a subpath component. 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.

NVD の説明

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.