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.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Fix
- Fixed in 1.51.0
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
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.
Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.
Read the original 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.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- zuke-build zuke
fixed in 1.51.0
References 4
GitHub · zuke-build/zuke
Questions about CVE-2026-119287
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: github.com
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: github.com
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: github.com
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: cve.now feed data