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TI-2026-38865 Aliases CVE-2026-53869GHSA-4pqm-j46f-795x

Hermes Agent < 0.16.0 - DNS Rebinding Bypass via WebSocket Endpoints

Priority MEDIUM 44CWE-306Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Security bypass
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-306.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00592 48th percentileScored 2026-11-07
Fix Fixed hermes-agent (NousResearch): 0.16.0hermes-agent (PyPI): 0.16.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
NousResearchhermes-agentbefore 0.16.00.16.0Patch availableCNA
—hermes-agent (PyPI)before 0.16.00.16.0Patch availableGHSA-4pqm-j46f-795x
  • hermes-agent VendorNousResearch Affected before 0.16.0 Fixed in 0.16.0 Patch available CNA
  • hermes-agent (PyPI) Vendor— Affected before 0.16.0 Fixed in 0.16.0 Patch available GHSA-4pqm-j46f-795x

Remediation

  • Fix · CNA hermes-agent (NousResearch) Fixed in 0.16.0
  • Fix · GHSA-4pqm-j46f-795x hermes-agent (PyPI) Fixed in 0.16.0 Advisory →

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    NousResearch hermes-agent 0.16.0

    2 records Highest priority Priority MEDIUM 2 MEDIUM

    Other records, highest priority first

    • TI-2026-38866 Hermes Agent < 0.16.0 - Sensitive File Permission Vulnerability in Store FilesPriority MEDIUM 63
    Show all 2 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-53869
  2. 2026-10-03 Alias added: GHSA-4pqm-j46f-795x
  3. 2026-10-25 EPSS moved to the below the 50th percentile

References

Patch 1

Advisory 1

Other 4

  • TI-2026-50258 Hermes Agent 0.18.2 - 0.21.0 RCE via git core.fsmonitor Config Injection CVSS 4.0HIGH 8.6
  • TI-2026-12325 NousResearch hermes-agent Live Webhook Endpoint base.py extract_media path traversal CVSS 4.0MEDIUM 6.9
  • TI-2026-08962 NousResearch hermes-agent Webhook Endpoint feishu.py _handle_webhook_request resource consumption CVSS 4.0MEDIUM 6.9
  • TI-2026-08959 NousResearch hermes-agent run_agent.py _compress_context injection CVSS 4.0MEDIUM 6.9
  • TI-2026-08958 NousResearch hermes-agent skills_tool.py skill_view injection CVSS 4.0MEDIUM 6.9
  • TI-2026-08218 NousResearch hermes-agent Environment Variable code_execution_tool.py execute_code sandbox CVSS 4.0MEDIUM 6.9
See all 44 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences