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TI-2026-53970 Aliases CVE-2026-77339GHSA-5gm3-9crp-6g3v

Process Compose: Browser DNS rebinding lets websites control local process-compose MCP tools

Priority MEDIUM 56CWE-306Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Passive
Attack complexity
Low
Attack requirements
Present
Impact type
Security bypass
Confidentiality · integrity · availability
Low · Low · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-306.

Summary

Process Compose is a scheduler and orchestrator for non-containerized applications. Prior to 1.120.0, the MCP SSE listener in src/mcp/server.go accepts browser-origin requests to /sse and the returned message endpoint without validating the Host header, validating the Origin header, or authenticating the caller. When MCP SSE is enabled, a malicious website can use DNS rebinding to reach the loopback listener and issue MCP requests. If expose_control_tools is enabled, the attacker can enumerate process state, read or search logs, truncate logs, and start, stop, restart, or scale local processes; configured user-defined tools can expose additional commands and output. The Gin REST API token middleware does not protect this separately started MCP listener. This issue is fixed in version 1.120.0.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00256 17th percentileScored 2026-11-07
Fix Fixed process-compose (F1bonacc1): 1.120.0github.com/f1bonacc1/process-compose (Go): 1.120.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
F1bonacc1process-composebefore 1.120.01.120.0Patch availableCNA
—github.com/f1bonacc1/process-compose (Go)before 1.120.01.120.0Patch availableGHSA-5gm3-9crp-6g3v
  • process-compose VendorF1bonacc1 Affected before 1.120.0 Fixed in 1.120.0 Patch available CNA
  • github.com/f1bonacc1/process-compose (Go) Vendor— Affected before 1.120.0 Fixed in 1.120.0 Patch available GHSA-5gm3-9crp-6g3v

Remediation

  • Fix · CNA process-compose (F1bonacc1) Fixed in 1.120.0
  • Fix · GHSA-5gm3-9crp-6g3v github.com/f1bonacc1/process-compose (Go) Fixed in 1.120.0 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-77339
  2. 2026-10-03 Alias added: GHSA-5gm3-9crp-6g3v

References

Other 4

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences