| Component | Hermes Agent |
| Severity | high (CVSS 7.5) |
| CVSS vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| Published (NVD) | 2026-06-17 |
| Last modified | 2026-06-18 |
| Affected versions | < 0.16.0 read from the advisory text: NVD has not published CPE data yet |
| Fixed in | 0.16.0 |
| Weakness | CWE-306 |
| CISA KEV | not listed |
NVD 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.
What to do
- Upgrade Hermes Agent to
0.16.0or later. - Do not expose the component's API or UI to the internet without authentication in front of it.
Sources
- NVD: CVE-2026-53869
- https://github.com/NousResearch/hermes-agent/commit/d9ec90585cf7616b5972e44cf8d92bb569fc3feb
- https://github.com/NousResearch/hermes-agent/pull/30221
- https://github.com/NousResearch/hermes-agent/pull/31685
- https://github.com/NousResearch/hermes-agent/releases/tag/v2026.6.5
- https://www.vulncheck.com/advisories/hermes-agent-dns-rebinding-bypass-via-websocket-endpoints
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