CVE-2026-57860

Description

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.

References

• https://github.com/tailcallhq/forgecode
• https://github.com/tailcallhq/forgecode/commit/68ca3a3a26c73c38a700453d3d021b5bbdc15dbd
• https://github.com/tailcallhq/forgecode/issues/3022
• https://github.com/tailcallhq/forgecode/issues/3252
• https://www.vulncheck.com/advisories/forgecode-arbitrary-code-execution-via-unvetted-mcp-json-in-untrusted-repository