| Component | Hermes Agent |
| Severity | medium (CVSS 4.3) |
| CVSS vector | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L |
| Published (NVD) | 2026-09-01 |
| Last modified | 2026-09-02 |
| Affected versions | not published yet, see the advisory |
| Fixed in | see the vendor advisory |
| Weakness | CWE-404 |
| CISA KEV | not listed |
NVD description
A vulnerability has been found in NousResearch hermes-agent up to 0.18.2. This affects the function HermesACPAgent.prompt of the file acp_adapter/session.py of the component ACP Prompt Workflow. Such manipulation leads to denial of service. The attack may be performed from remote. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
What to do
- NVD lists no fixed version yet: follow the vendor advisory below and keep Hermes Agent off the public internet until a fix ships.
- Do not expose the component's API or UI to the internet without authentication in front of it.
Sources
- NVD: CVE-2026-84288
- https://github.com/hackerguopeng/cve/tree/main/Hermes_ACP_Queued_Prompt_DoS_Report
- https://vuldb.com/cve/CVE-2026-84288
- https://vuldb.com/submit/882873
- https://vuldb.com/vuln/397719
- https://vuldb.com/vuln/397719/cti
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