---
id: CVE-2020-27534
aliases:
  - GHSA-6hwg-w5jg-9c6x
title: Path Traversal in Moby builder
summary: Path Traversal in Moby builder
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'
vendor: moby
product: github.com/moby/moby
ecosystem: go
affected:
  - github.com/moby/moby < 19.03.9
  - github.com/docker/docker < 19.03.9
patched:
  - github.com/moby/moby 19.03.9
  - github.com/docker/docker 19.03.9
published: '2024-01-31'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T03:50:09.240988294Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-6hwg-w5jg-9c6x'
references:
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2020-27534'
  - url: 'https://github.com/moby/buildkit/pull/1462'
  - url: 'https://github.com/moby/moby/pull/40877'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=1921154'
  - url: >-
      http://web.archive.org/web/20200530054359/https://docs.docker.com/engine/release-notes
tags:
  - osv
  - go
epss: 0.01766
epssPercentile: 0.77128
ingestedAt: '2026-09-12T03:13:01.759Z'
---

## Overview

util/binfmt_misc/check.go in Builder in Docker Engine before 19.03.9 calls os.OpenFile with a potentially unsafe qemu-check temporary pathname, constructed with an empty first argument in an ioutil.TempDir call.

## Affected packages

- `github.com/moby/moby < 19.03.9`
- `github.com/docker/docker < 19.03.9`

## Remediation

Upgrade to a patched release:

- `github.com/moby/moby 19.03.9`
- `github.com/docker/docker 19.03.9`