CVE-2026-84289

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

MEDIUM
4.3
CVSS Score
Published: September 1, 2026 at 09:45 PM UTC
Updated: September 2, 2026 at 04:17 PM UTC
1 product affected across 1 vendorHermes Agent

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Severity
MEDIUM4.3
Exploit prediction
EPSS 0.5%
SSVC
PoC

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (5)

VDB EntryTechnical Description
Source: cverecord
https://vuldb.com/vuln/397720
SignaturePermissions Required
Source: cverecord
https://vuldb.com/vuln/397720/cti
Third Party Advisory
Source: cverecord
https://vuldb.com/cve/CVE-2026-84289
Third Party Advisory
Source: cverecord
https://vuldb.com/submit/882960

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.3MEDIUMVulDB
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-789CWE-400

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