---
id: "CVE-2026-121614"
kind: "vulnerability"
aliases: ["CVE-2026-121614"]
title: "Docker Sandboxes: repository Git config can run host programs outside isolation"
severity: "high"
cvss: 7.1
epss: null
exploited: false
status: "open"
category: "other"
products: []
ecosystems: []
tags: ["developers", "docker-sandboxes", "git", "other", "sbx"]
not_affected_if: ["not-using-docker-sandboxes", "read-only-host-mount-clone-mode"]
published_at: "2026-11-03T22:19:46+00:00"
first_seen_at: "2026-11-03T23:15:09+00:00"
updated_at: "2026-11-03T23:16:11+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-121614", "first_seen_at": "2026-11-03T23:15:09+00:00"}]
---

# Docker Sandboxes: repository Git config can run host programs outside isolation

Docker Sandboxes versions 0.31.0 before 0.50.0 fail to neutralize Git settings stored in a repository, such as core.fsmonitor, when running certain host-side Git commands. An attacker who can edit a host repository's Git configuration can make a later fetch or sbx kit push run an external program on the host with the user's permissions, outside the sandbox isolation.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed Docker Sandboxes (sbx) version and confirm whether it is below `0.50.0`.
- Look at repositories mounted read-write into direct-mode sandboxes for changes to `.git/config` that set `core.fsmonitor` or other external-program Git settings.

## Timeline

- 2026-11-03T23:15:09+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-121614

## Documents

- [fix] Release notes: github.com https://github.com/docker/sbx-releases/releases/tag/v0.50.0

## From the sources

Docker Sandboxes versions 0.31.0 before 0.50.0 do not neutralize repository-controlled Git configuration when running certain host-side Git commands. An attacker who can modify a host repository's Git configuration, for example through a direct-mode sandbox with the repository mounted read-write, can configure core.fsmonitor or another Git setting that invokes an external program. Git can execute the program during a later clone-mode fetch or, starting in version 0.39.0, an sbx kit push initiated by the user. The program runs on the host with the invoking user's permissions, outside the sandbox's microVM isolation. The read-only host repository mount provided to a clone-mode sandbox does not itself allow that sandbox to modify the host repository's Git configuration. The issue is fixed in version 0.50.0.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_