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.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements Present

User Interaction Passive

Vulnerable System Confidentiality Impact Low

Vulnerable System Integrity Impact Low

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact Low

Subsequent System Integrity Impact High

Subsequent System Availability Impact None

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation poc

Automatable no

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
F1bonacc1 process-compose affected
Version Status Constraints
< 1.120.0 affected —

No data.

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Project Subscriptions

No data.

Advisories
Source ID Title
Github GHSA Github GHSA GHSA-5gm3-9crp-6g3v Process Compose: Browser DNS rebinding lets websites control local process-compose MCP tools
Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/F1bonacc1/process-compose/commit/6ffa74f462cd2fa4f8dc1ee63c70b793b298c858 cve-icon cve-icon
https://github.com/F1bonacc1/process-compose/releases/tag/v1.120.0 cve-icon cve-icon
https://github.com/F1bonacc1/process-compose/security/advisories/GHSA-5gm3-9crp-6g3v cve-icon cve-icon cve-icon
History

Fri, 18 Sep 2026 21:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Fri, 18 Sep 2026 16:45:00 +0000

Type Values Removed Values Added
Description 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.
Title Process Compose: Browser DNS rebinding lets websites control local process-compose MCP tools
Weaknesses CWE-306
CWE-346
References
Metrics cvssV4_0

{'score': 5.1, 'vector': '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'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-09-18T16:49:46.487Z

Reserved: 2026-08-20T19:24:11.618Z

Link: CVE-2026-77339

cve-icon Vulnrichment

Updated: 2026-09-18T16:49:41.201Z

cve-icon NVD

Status : Received

Published: 2026-09-18T17:17:00.663

Modified: 2026-09-18T17:17:00.663

Link: CVE-2026-77339

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses