Vulnerability in Nousresearch Hermes-Agent
CVE-2026-9366
A vulnerability was found in NousResearch hermes-agent 2026.4.23. The impacted element is the function _scan_context_content of the file agent/prompt_builder.py. The manipulation results in injection. The attack may be performed from remote. The exploit has been made public and could 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 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.005 (42.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 43rd percentile — 42.7% 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 2026.4.23
Weakness classification (CWE)
References
- vuldb.com/vuln/365329 (technical-description, vdb-entry)
- vuldb.com/vuln/365329/cti (signature, permissions-required)
- vuldb.com/submit/812227 (third-party-advisory)
- gist.github.com/YLChen-007/581fd92de5548fbaacb2092e848a75cc (exploit)
Frequently asked questions
- What is CVE-2026-9366?
- CVE-2026-9366 is a high-severity vulnerability in Nousresearch Hermes-Agent, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 7.3/10. Published 2026-05-24.
- How severe is CVE-2026-9366?
- High severity. CVSS v3 base score is 7.3 out of 10.