CVE-2026-57860 HIGH

CVE-2026-57860: ForgeCode Arbitrary Code Execution via Unvetted .mcp.json in Untrusted Repository

Vendor Tailcallhq
Product forgecode
Weakness CWE-829 · Inclusion from untrusted sphere
Published July 17, 2026
Last update July 20, 2026

CVSS base score

8.4/10
Attack vector Local
Attack complexity Low
Privileges required None
User interaction
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

What the vulnerability does

01Description

ForgeCode (tailcallhq/forgecode), an AI pair-programming CLI, automatically loads and executes the MCP servers defined in a repository's .mcp.json file on startup without user confirmation. A malicious repository can supply a crafted .mcp.json whose mcpServers entries specify arbitrary command and args values (for example, command: bash with args: ['-c', 'touch /tmp/pwned']). When a user runs the forge CLI inside a cloned untrusted repository, the specified commands are spawned with the invoking user's privileges, resulting in arbitrary code execution. This provides a reliable initial-access and persistence primitive against developers who evaluate untrusted repositories with ForgeCode.

Key dates

02Disclosure timeline

July 17, 2026 CVE published
July 20, 2026 Record updated