CVE-2026-84288: Nousresearch Hermes-Agent

Medium severity, CVSS 4.3. EPSS: 0.5% chance of exploitation in the next 30 days.

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.

Affected products

• Nousresearch Hermes-Agent: version 0.18.0 only; version 0.18.1 only; version 0.18.2 only

Published 2026-09-01. Last modified 2026-09-02.