{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-53869: Hermes Agent < 0.16.0 - DNS Rebinding Bypass via WebSocket Endpoints","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-53869","status":"final","version":"1","initial_release_date":"2026-06-17T17:57:30.978Z","current_release_date":"2026-06-17T17:57:30.978Z","revision_history":[{"date":"2026-06-17T17:57:30.978Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"description","text":"Hermes Agent before 0.16.0 contains a DNS rebinding vulnerability in WebSocket endpoints that allows remote attackers to bypass Host and Origin validation. FastAPI HTTP middleware does not execute for WebSocket upgrade requests on /api/pty, /api/ws, /api/pub, and /api/events endpoints, enabling attackers to exploit DNS rebinding and inject malicious commands or read terminal output.","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-53869 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-53869"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-53869"},{"category":"external","summary":"Release Notes","url":"https://github.com/NousResearch/hermes-agent/releases/tag/v2026.6.5"},{"category":"external","summary":"Researcher Pull Request","url":"https://github.com/NousResearch/hermes-agent/pull/30221"},{"category":"external","summary":"Maintainer Pull Request","url":"https://github.com/NousResearch/hermes-agent/pull/31685"},{"category":"external","summary":"Patch Commit","url":"https://github.com/NousResearch/hermes-agent/commit/d9ec90585cf7616b5972e44cf8d92bb569fc3feb"},{"category":"external","summary":"vulncheck.com","url":"https://www.vulncheck.com/advisories/hermes-agent-dns-rebinding-bypass-via-websocket-endpoints"}]},"product_tree":{"branches":[{"category":"vendor","name":"NousResearch","branches":[{"category":"product_name","name":"hermes-agent","branches":[{"category":"product_version_range","name":"<0.16.0","product":{"name":"NousResearch hermes-agent <0.16.0","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:nousresearch:hermes-agent:*:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"0.16.0","product":{"name":"NousResearch hermes-agent 0.16.0","product_id":"CSAFPID-2","product_identification_helper":{"cpe":"cpe:2.3:a:nousresearch:hermes-agent:*:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-53869","title":"Hermes Agent < 0.16.0 - DNS Rebinding Bypass via WebSocket Endpoints","notes":[{"category":"description","text":"Hermes Agent before 0.16.0 contains a DNS rebinding vulnerability in WebSocket endpoints that allows remote attackers to bypass Host and Origin validation. FastAPI HTTP middleware does not execute for WebSocket upgrade requests on /api/pty, /api/ws, /api/pub, and /api/events endpoints, enabling attackers to exploit DNS rebinding and inject malicious commands or read terminal output.","title":"CVE description"}],"product_status":{"known_affected":["CSAFPID-1"],"fixed":["CSAFPID-2"]},"scores":[{"cvss_v4":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","baseScore":8.7,"baseSeverity":"HIGH"},"products":["CSAFPID-1"]}],"remediations":[{"category":"vendor_fix","details":"Update to a fixed version: 0.16.0.","product_ids":["CSAFPID-1"],"url":"https://github.com/NousResearch/hermes-agent/commit/d9ec90585cf7616b5972e44cf8d92bb569fc3feb"}]}]}