CVE-2026-84289

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

Published Sep 1, 2026 CVSS 4.0 · 5.3 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title NousResearch hermes-agent MCP Tool mcp_tool.py list_tools memory allocation
First Time appeared Nousresearch
Nousresearch hermes-agent
Weaknesses CWE-400
CWE-789
CPEs cpe:2.3:a:nousresearch:hermes-agent:*:*:*:*:*:*:*:*
Vendors & Products Nousresearch
Nousresearch hermes-agent
References
Metrics cvssV2_0

{'score': 4, 'vector': 'AV:N/AC:L/Au:S/C:N/I:N/A:P/E:POC/RL:ND/RC:UR'}

cvssV3_0

{'score': 4.3, 'vector': 'CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R'}

cvssV3_1

{'score': 4.3, 'vector': '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'}

cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulDB
Published
Updated
Sep 2, 2026, 4:01 PM
Reserved
Sep 1, 2026, 3:48 PM
Status
Deferred
Published
Sep 1, 2026, 10:17 PM
Modified
Sep 2, 2026, 4:17 PM