Vulnerability in Nousresearch Hermes-Agent
CVE-2026-84288
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.005 (39.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 39th percentile — 39.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002
Affected products
- Nousresearch Hermes-Agent — versions 0.18.0, 0.18.1, 0.18.2
Weakness classification (CWE)
References
- vuldb.com/vuln/397719 (technical-description, vdb-entry)
- vuldb.com/vuln/397719/cti (signature, permissions-required)
- vuldb.com/cve/CVE-2026-84288 (third-party-advisory)
- vuldb.com/submit/882873 (third-party-advisory)
- github.com/hackerguopeng/cve/tree/main/Hermes_ACP_Queued_Prompt_DoS_Report (exploit)
Frequently asked questions
- What is CVE-2026-84288?
- CVE-2026-84288 is a medium-severity vulnerability in Nousresearch Hermes-Agent, classified under Improper Resource Shutdown or Release. CVSS score: 4.3/10. Published 2026-09-01.
- How severe is CVE-2026-84288?
- Medium severity. CVSS v3 base score is 4.3 out of 10.