CVE-2026-53869Network attack vector

Command injection via unchecked WebSocket upgrades

Published Jun 17, 2026 · Updated Jun 17, 2026

DNS rebinding in Nous Research Hermes Agent before 0.16.0 allows remote attackers to inject commands through WebSocket endpoints. FastAPI HTTP middleware does not run for WebSocket upgrades, leaving /api/pty, /api/ws, /api/pub, and /api/events without the existing Host and Origin checks. A malicious site reached through the dashboard host's browser can access the loopback service, exposing command execution and terminal output.

CVSS severity8.7
High
EPSS probability0.59%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

DNS rebinding in Nous Research Hermes Agent before 0.16.0 allows remote attackers to inject commands through WebSocket endpoints. FastAPI HTTP middleware does not run for WebSocket upgrades, leaving /api/pty, /api/ws, /api/pub, and /api/events without the existing Host and Origin checks. A malicious site reached through the dashboard host's browser can access the loopback service, exposing command execution and terminal output.

The record

CVE
CVE-2026-53869
Published
Jun 17, 2026
Updated
Jun 17, 2026
Vendor
Nous Research
Product
Hermes Agent
Classifications
CWE-306, T1059
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 17, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <0.16.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Nous Research · Hermes Agentversion=0 <0.16.0

Published CVSS scores

7.5VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
8.7VulnCheckCVSS: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 describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function
T1059Command and Scripting Interpreter

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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