CVE-2026-57860
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.20%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 4.0
- 8.4 HIGHCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.20% probability · 10th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-829
- Source
- disclosure@vulncheck.com
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
- https://github.com/tailcallhq/forgecode/issues/3022
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.