CVE-2026-53869 Details
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.
A DNS rebinding vulnerability has been identified in Hermes Agent versions prior to 0.16.0. This vulnerability exists in WebSocket endpoints, allowing remote attackers to bypass Host and Origin validation. The issue arises because FastAPI HTTP middleware does not process WebSocket upgrade requests on several endpoints, including /api/pty, /api/ws, /api/pub, and /api/events. As a result, attackers can exploit the DNS rebinding to inject malicious commands or intercept terminal output.
Users can update to Hermes Agent version 0.16.0 or later, where this vulnerability has been fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Jun 17, 2026CISA-ADP
Assessed Jun 18, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/NousResearch/hermes-agent/commit/d9ec90585cf7616b5972e44cf8d92bb569fc3feb | [email protected] | Source CodeVendor |
| https://github.com/NousResearch/hermes-agent/pull/30221 | [email protected] | Issue TrackingVendor |
| https://github.com/NousResearch/hermes-agent/pull/31685 | [email protected] | Issue TrackingVendor |
| https://github.com/NousResearch/hermes-agent/releases/tag/v2026.6.5 | [email protected] | Release NotesVendor |
| https://www.vulncheck.com/advisories/hermes-agent-dns-rebinding-bypass-via-websocket-endpoints | [email protected] | AdvisoryBundleRemedy |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-306 | Missing Authentication for Critical Function | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| NousResearch Hermes Agent | < 0.16.0 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 18, 2026 | CVE Modified | CISA-ADP |
| Jun 17, 2026 | New CVE Received | [email protected] |