CVE-2026-77339 Details
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.
A vulnerability in Process Compose's MCP SSE listener prior to version 1.120.0 allows browser-origin requests to be accepted without proper validation of the Host and Origin headers, or authentication of the caller. This flaw can be exploited by a malicious website using DNS rebinding to send requests to the loopback listener, potentially controlling local processes through the MCP tools. The issue is particularly concerning when the 'expose_control_tools' feature is enabled, as it allows enumeration and manipulation of process states and logs, and control over local processes via the MCP tools.
Users can update to Process Compose version 1.120.0 or later, where this vulnerability has been fixed. Instructions for downloading the latest version are available on the Process Compose GitHub releases page.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Sep 18, 2026CISA-ADP
Assessed Sep 18, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/F1bonacc1/process-compose/security/advisories/GHSA-5gm3-9crp-6g3v | CISA-ADP | AdvisoryExploitRemedyVendor |
| https://github.com/F1bonacc1/process-compose/commit/6ffa74f462cd2fa4f8dc1ee63c70b793b298c858 | [email protected] | Source CodeVendor |
| https://github.com/F1bonacc1/process-compose/releases/tag/v1.120.0 | [email protected] | Release NotesVendor |
| https://github.com/F1bonacc1/process-compose/security/advisories/GHSA-5gm3-9crp-6g3v | [email protected] | AdvisoryExploitRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-306 | Missing Authentication for Critical Function | [email protected] |
| CWE-346 | Origin Validation Error | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| F1bonacc1 Process Compose | <= 1.116.0 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Sep 18, 2026 | New CVE Received | [email protected] |
| Sep 18, 2026 | CVE Modified | CISA-ADP |