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.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
Low
Partial disruption
CVSS Vector v4.0
Weakness Type (CWE)
Vulnerable Products
nousresearch:hermes-agent
References 5
https://vuldb.com/vuln/397720
VDB-397720 | NousResearch hermes-agent MCP Tool mcp_tool.py list_tools memory allocation
https://vuldb.com/vuln/397720/cti
VDB-397720 | CTI Indicators (IOB, IOC, IOA)
https://vuldb.com/cve/CVE-2026-84289
CVE-2026-84289 | CVE Analysis and Report
https://vuldb.com/submit/882960
Submit #882960 | NousResearch hermes-agent 0.18.0 Denial of Service
https://github.com/lche511/cve/blob/main/Hermes_MCP_Tool_Resource_Amplification…
NVD