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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| NousResearch | hermes-agent | < 0.16.0 | 0.16.0 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | hermes-agent | < 0.16.0 | 0.16.0 | GHSA-4pqm-j46f-795x |
References
- hermes-agent 2026.6.5 Release Notes release-notes
- Researcher Pull Request issue-tracking patch
- Maintainer Pull Request issue-tracking patch
- Patch Commit patch
- https://www.vulncheck.com/advisories/hermes-agent-dns-rebinding-bypass-via-websocket-endpoints third-party-advisory