---
id: CVE-2026-77339
title: >-
  Process Compose is a scheduler and orchestrator for non-containerized
  applications
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 …
severity: medium
cvss: 5.1
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:H/SA:N'
cwe:
  - CWE-306
  - CWE-346
vendor: f1bonacc1
product: github.com/f1bonacc1/process-compose
affected:
  - github.com/f1bonacc1/process-compose < 1.120.0
patched:
  - github.com/f1bonacc1/process-compose 1.120.0
published: '2026-09-18'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T21:25:27.050'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-77339'
references:
  - url: >-
      https://github.com/F1bonacc1/process-compose/commit/6ffa74f462cd2fa4f8dc1ee63c70b793b298c858
    label: security-advisories@github.com
  - url: 'https://github.com/F1bonacc1/process-compose/releases/tag/v1.120.0'
    label: security-advisories@github.com
  - url: >-
      https://github.com/F1bonacc1/process-compose/security/advisories/GHSA-5gm3-9crp-6g3v
    label: security-advisories@github.com
  - url: >-
      https://github.com/F1bonacc1/process-compose/security/advisories/GHSA-5gm3-9crp-6g3v
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://github.com/advisories/GHSA-5gm3-9crp-6g3v'
  - url: 'https://github.com/F1bonacc1/process-compose'
tags:
  - nvd
  - ghsa
  - go
  - cve.org
  - exploit-available
  - osv
epss: 0.00256
epssPercentile: 0.15314
aliases:
  - GHSA-5gm3-9crp-6g3v
ecosystem: go
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-18T16:49:18.961229Z'
cvssSource: cna
ingestedAt: '2026-09-18T16:45:41.405Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-77339)

Affected packages:

- `github.com/f1bonacc1/process-compose < 1.120.0`

Patched in:

- `github.com/f1bonacc1/process-compose 1.120.0`

Source: https://github.com/advisories/GHSA-5gm3-9crp-6g3v