CVE-2026-53869 PUBLISHED

Hermes Agent < 0.16.0 - DNS Rebinding Bypass via WebSocket Endpoints

Assigner: VulnCheck
Reserved: 10.06.2026 Published: 17.06.2026 Updated: 17.06.2026

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.

CVSS Vector: 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
CVSS Score: 8.7

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	None	Integrity	None
Attack Requirements	None	Availability	High	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS Score: 7.5

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	None
Privileges Required	None	Integrity Impact	None
User Interaction	None	Availability Impact	High

CVSS 3.1

Product Status

Vendor	NousResearch
Product	hermes-agent
Versions	Default: unaffected affected from 0 to 0.16.0 (excl.) Version 0.16.0 is unaffected

CVE-2026-53869 PUBLISHED

Hermes Agent < 0.16.0 - DNS Rebinding Bypass via WebSocket Endpoints

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Product Status

Credits

References

Problem Types