CVE-2026-77339: CWE-306: Missing Authentication for Critical Function in F1bonacc1 process-compose
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.
AI Analysis
Technical Summary
The MCP SSE listener in process-compose versions before 1.120.0 does not validate critical headers or authenticate callers, enabling DNS rebinding attacks from malicious websites. This can lead to unauthorized enumeration of process state, log reading and truncation, and control over local processes including starting, stopping, restarting, or scaling them. The Gin REST API token middleware does not protect this listener, increasing exposure. The issue is resolved in version 1.120.0.
Potential Impact
An attacker can exploit this vulnerability to perform unauthorized actions on the local process-compose instance, including enumerating process states, reading and truncating logs, and controlling local processes. This can lead to information disclosure and unauthorized process manipulation. The severity is rated medium with a CVSS 4.0 score of 5.1.
Mitigation Recommendations
Upgrade process-compose to version 1.120.0 or later, where this vulnerability is fixed. Until then, disabling the expose_control_tools setting can reduce the attack surface. No other mitigations are specified.
CVE-2026-77339: CWE-306: Missing Authentication for Critical Function in F1bonacc1 process-compose
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.
CVSS v4.0
Score 5.1medium
Affected software
F1bonacc1
process-compose
pkg:github/f1bonacc1/process-composeRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The MCP SSE listener in process-compose versions before 1.120.0 does not validate critical headers or authenticate callers, enabling DNS rebinding attacks from malicious websites. This can lead to unauthorized enumeration of process state, log reading and truncation, and control over local processes including starting, stopping, restarting, or scaling them. The Gin REST API token middleware does not protect this listener, increasing exposure. The issue is resolved in version 1.120.0.
Potential Impact
An attacker can exploit this vulnerability to perform unauthorized actions on the local process-compose instance, including enumerating process states, reading and truncating logs, and controlling local processes. This can lead to information disclosure and unauthorized process manipulation. The severity is rated medium with a CVSS 4.0 score of 5.1.
Mitigation Recommendations
Upgrade process-compose to version 1.120.0 or later, where this vulnerability is fixed. Until then, disabling the expose_control_tools setting can reduce the attack surface. No other mitigations are specified.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-08-20T19:24:11.618Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6aad6b0955bf5e2cf541928e
Added to database: 09/18/2026, 16:47:05 UTC
Last enriched: 09/18/2026, 17:02:27 UTC
Last updated: 09/19/2026, 01:09:45 UTC
Views: 7
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