Process Compose: Browser DNS rebinding lets websites control local process-compose MCP tools
## Summary A malicious website can use DNS rebinding to control a developer's local process-compose MCP SSE listener when MCP SSE is enabled. The vulnerable path accepts browser-origin requests before any Host validation, Origin validation, or caller-secret check, then dispatches the requests into process-compose MCP tools. This advisory covers `https://github.com/F1bonacc1/process-compose`, confirmed at commit `d56aa59df04b72f8644811ac581a051bec05e485`. The issue is in the MCP SSE transport, not the Gin REST API. The REST API token middleware protects REST routes, but the MCP listener is started separately and does not inherit that protection. ## Affected Code Root cause: ```text src/types/mcp.go:24-30 SSE is the default MCP transport when mcp_server.transport is omitted. src/types/mcp.go:64-70 SSE configuration requires only host and port. There is no auth, Host allowlist, Origin allowlist, or caller-secret field. src/mcp/server.go:203-214 The server starts server.NewSSEServer(s.mcpServer) directly on the configured address. src/api/routes.go:32-39 X-PC-Token-Key middleware is installed on the Gin REST router, not on the MCP SSE listener. ``` Impact surface: ```text src/mcp/mcp_manager.go:33-38 expose_control_tools registers built-in process-compose control tools. src/mcp/control_tools.go:26-116 The registered tools start, stop, restart, scale, read logs, search logs, and truncate logs. src/mcp/control_tools.go:121-142 The registered tools return project and process state.
GO-2026-6515
Revision 1
Process Compose: Browser DNS rebinding lets websites control local process-compose MCP tools in github.com/f1bonacc1/process-compose
Process Compose: Browser DNS rebinding lets websites control local process-compose MCP tools in github.com/f1bonacc1/process-compose
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:GO-2026-6515
github.com/f1bonacc1/process-compose
Source reference: /affected/0/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 1.120.0
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.120.0"
}
]
}
],
"package": {
"name": "github.com/f1bonacc1/process-compose",
"purl": "pkg:golang/github.com/f1bonacc1/process-compose",
"ecosystem": "Go"
},
"database_specific": {
"source": "https://vuln.go.dev/ID/GO-2026-6515.json"
},
"ecosystem_specific": {}
}
]- Related CVEs
- CVE-2026-77339
Source reference:
/aliases
Publisher severity
No explicit severity was provided.
- Event
- #23363 · Revision 1
- Added to Heist Feed
- Publisher date
GHSA-5gm3-9crp-6g3v
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:GHSA-5gm3-9crp-6g3v
github.com/f1bonacc1/process-compose
Source reference: /affected/0/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 1.120.0
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.120.0"
}
]
}
],
"package": {
"name": "github.com/f1bonacc1/process-compose",
"purl": "pkg:golang/github.com/f1bonacc1/process-compose",
"ecosystem": "Go"
},
"database_specific": {
"source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-5gm3-9crp-6g3v/GHSA-5gm3-9crp-6g3v.json"
}
}
]- Related CVEs
- CVE-2026-77339
Source reference:
/aliases
Publisher severity
No explicit severity was provided.
- Event
- #23414 · Revision 1
- Added to Heist Feed
- Publisher date