Medium 4.3Published Sep 1, 2026

CVE-2026-84289NousResearch hermes-agent MCP Tool mcp_tool.py list_tools memory allocation

Updated under an hour ago (2026-10-19 07:10 UTC)

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No exploitation reported and no EPSS estimate yet.

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Every CVE for NousResearch hermes-agent

Exploited in the last 30 days

A vulnerability was found in NousResearch hermes-agent up to 0.18.2. This vulnerability affects the function list_tools of the file tools/mcp_tool.py of the component MCP Tool. Performing a manipulation results in uncontrolled memory allocation. It is possible to initiate the attack remotely. 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.

CVSS: 4.3 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R
Weakness (CWE): CWE-789, CWE-400
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: VulDB
NVD analysis: Deferred
Record last updated: Sep 2, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

NousResearch hermes-agent nousresearch:hermes-agent	0.18.0; 0.18.1; 0.18.2	CNA record

References

https://vuldb.com/vuln/397720vdb-entry, technical-description
https://vuldb.com/vuln/397720/ctisignature, permissions-required
https://vuldb.com/cve/CVE-2026-84289third-party-advisory
https://vuldb.com/submit/882960third-party-advisory
https://github.com/lche511/cve/blob/main/Hermes_MCP_Tool_Resource_Amplification_DoS_Report/REPORT.mdexploit

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.