# CVE-2026-33748: docker.io: BuildKit is a toolkit for converting source code to build artifacts in an efficient, expressive and repeatable manner

CVE-2026-33748 is fixed in 3 products on 1 platform, first by DEBIAN-CVE-2026-33748, released March 27, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-33748
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0048
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Mar 27, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | docker.io Debian 13.5 (trixie) | 26.1.5+dfsg1-9+deb13u1 | [DEBIAN-CVE-2026-33748](https://patchblox.com/security/data/fix/linux/debian-cve-2026-33748.md) | Mar 27, 2026 |
| Linux | docker.io Debian 14 | 28.5.2+dfsg4-3 | [DEBIAN-CVE-2026-33748](https://patchblox.com/security/data/fix/linux/debian-cve-2026-33748.md) | Mar 27, 2026 |
| Linux | docker.io Ubuntu 20.04 LTS (focal) | 26.1.3-0ubuntu1~20.04.1+esm2 | [docker.io 26.1.3-0ubuntu1~20.04.1+esm2](https://patchblox.com/security/data/fix/linux/ubuntu-focal-docker.io-26.1.3-0ubuntu1-20.04.1-esm2.md) | May 15, 2026 |
| Linux | docker.io Ubuntu 22.04.1 LTS (jammy) | 29.1.3-0ubuntu3~22.04.2 | [docker.io 29.1.3-0ubuntu3~22.04.2](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-docker.io-29.1.3-0ubuntu3-22.04.2.md) | May 15, 2026 |
| Linux | docker.io Ubuntu 24.04.5 LTS (noble) | 29.1.3-0ubuntu3~24.04.2 | [docker.io 29.1.3-0ubuntu3~24.04.2](https://patchblox.com/security/data/fix/linux/ubuntu-noble-docker.io-29.1.3-0ubuntu3-24.04.2.md) | May 15, 2026 |
| Linux | docker.io Ubuntu 26.04.1 LTS (resolute) | 29.1.3-0ubuntu4.1 | [docker.io 29.1.3-0ubuntu4.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-docker.io-29.1.3-0ubuntu4.1.md) | Apr 21, 2026 |
| Linux | govulncheck-vulndb opensuse-leap 15.6 | 0.0.20260402T184258-150000.1.158.1 | [SUSE-SU-2026:1205-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1205-1.md) | Apr 7, 2026 |
| Linux | govulncheck-vulndb opensuse-leap 16.0 | 0.0.20260723T184607-160000.1.1 | [OPENSUSE-SU-2026:21483-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21483-1.md) | Jul 30, 2026 |
| Linux | runfinch-finch amzn 2023 | 1.17.0-1.amzn2023.0.1 | [ALAS2023-2026-1671](https://patchblox.com/security/data/fix/linux/alas2023-2026-1671.md) | May 11, 2026 |

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Data as of 2026-11-08T00:53:09Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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