Medium 5.1Published Sep 18, 2026

CVE-2026-77339Process Compose: Browser DNS rebinding lets websites control local process-compose MCP tools

Updated under an hour ago (2026-10-19 10:10 UTC)

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It affects F1bonacc1 process-compose. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for F1bonacc1 process-compose

Exploited in the last 30 days

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: 5.1 MEDIUM (v4.0, CNA)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
Weakness (CWE): CWE-306, CWE-346
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Sep 18, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

F1bonacc1 process-compose f1bonacc1:process_compose (from the name)	before 1.120.0	CNA record

References

https://github.com/F1bonacc1/process-compose/security/advisories/GHSA-5gm3-9crp-6g3vx-refsource-confirm
https://github.com/F1bonacc1/process-compose/commit/6ffa74f462cd2fa4f8dc1ee63c70b793b298c858x-refsource-misc
https://github.com/F1bonacc1/process-compose/releases/tag/v1.120.0x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.