CVE-2026-53869

HIGH 7.5

Hermes Agent < 0.16.0 - DNS Rebinding Bypass via WebSocket Endpoints

CVSS Score

7.5

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-306
Vendor	nousresearch
Product	hermes-agent
Published	Jun 17, 2026

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CVSS v3 Breakdown

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Affected Versions

NousResearch / hermes-agent

0 < 0.16.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/NousResearch/hermes-agent/releases/tag/v2026.6.5 github.com: https://github.com/NousResearch/hermes-agent/pull/30221 github.com: https://github.com/NousResearch/hermes-agent/pull/31685 github.com: https://github.com/NousResearch/hermes-agent/commit/d9ec90585cf7616b5972e44cf8d92bb569fc3feb vulncheck.com: https://www.vulncheck.com/advisories/hermes-agent-dns-rebinding-bypass-via-websocket-endpoints

Credits

Chia Min Jun Lennon