CVE-2026-53869
Deferred Deferred - Pending Action
DNS Rebinding in Hermes Agent WebSocket Endpoints

Publication date: 2026-06-17

Last updated on: 2026-06-17

Assigner: VulnCheck

Description
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.
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Meta Information
Published
2026-06-17
Last Modified
2026-06-17
Generated
2026-06-18
AI Q&A
2026-06-18
EPSS Evaluated
N/A
NVD
CVE-2026-53869
EUVD
EUVD-2026-37774
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
hermes_agent hermes_agent to 0.16.0 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-306 The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.
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Executive Summary

Hermes Agent versions before 0.16.0 have a DNS rebinding vulnerability in their WebSocket endpoints. This vulnerability allows remote attackers to bypass Host and Origin validation because the FastAPI HTTP middleware does not run for WebSocket upgrade requests on certain endpoints (/api/pty, /api/ws, /api/pub, and /api/events). As a result, attackers can exploit this to inject malicious commands or read terminal output.

Impact Analysis

This vulnerability can allow remote attackers to bypass security checks and gain unauthorized access to the system's terminal output or execute malicious commands. This can lead to unauthorized control over the affected system, potentially compromising its integrity and confidentiality.

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