CVE-2026-84289

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 v3 4.3 MEDIUM
CVSS v2.0 4.0 MEDIUM

4.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact LOW

Scope UNCHANGED

4.0^/10

CVSS v2.0 : MEDIUM

Vector : AV:N/AC:L/Au:S/C:N/I:N/A:P

Exploitability : 8.0 / Impact : 2.9

Access Vector NETWORK

Access Complexity LOW

Authentication SINGLE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact PARTIAL

References

Link	Resource
https://github.com/lche511/cve/blob/main/Hermes_MCP_Tool_Resource_Amplification_DoS_Report/REPORT.md
https://vuldb.com/cve/CVE-2026-84289
https://vuldb.com/submit/882960
https://vuldb.com/vuln/397720
https://vuldb.com/vuln/397720/cti

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-01 22:17

Updated : 2026-09-02 16:17

NVD link : CVE-2026-84289

Mitre link : CVE-2026-84289

CVE.ORG link : CVE-2026-84289

JSON object : View

Products Affected

No product.

CWE

CWE-400

Uncontrolled Resource Consumption

CWE-789

Memory Allocation with Excessive Size Value

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