{"id":"CVE-2026-77339","aliases":["GHSA-5gm3-9crp-6g3v"],"url":"https://o3.security/vulnerability/CVE-2026-77339","summary":"Process Compose: Browser DNS rebinding lets websites control local process-compose MCP tools","details":"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.","published":"2026-09-18T16:37:19.072Z","modified":"2026-09-19T03:47:23.935752193Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Go","name":"github.com/f1bonacc1/process-compose","fixedVersion":"1.120.0"}],"fix":{"url":"https://github.com/F1bonacc1/process-compose/commit/6ffa74f462cd2fa4f8dc1ee63c70b793b298c858","label":"F1bonacc1/process-compose@6ffa74f"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/77xxx/CVE-2026-77339.json"},{"type":"FIX","url":"https://github.com/F1bonacc1/process-compose/commit/6ffa74f462cd2fa4f8dc1ee63c70b793b298c858"},{"type":"WEB","url":"https://github.com/F1bonacc1/process-compose/releases/tag/v1.120.0"},{"type":"ADVISORY","url":"https://github.com/F1bonacc1/process-compose/security/advisories/GHSA-5gm3-9crp-6g3v"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-77339"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-19T03:47:23.935752193Z"}}