CVE-2026-84289: medium-severity vulnerability in NousResearch hermes-agent
NousResearch hermes-agent MCP Tool mcp_tool.py list_tools memory allocation
Published · Updated
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33Vexday Risk Score
No sign of exploitation. It has a public proof of concept.
ssvc Attendcvss 5.3epss 0.5%
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:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
Affected products
NousResearch · hermes-agentpublic PoCs found — 1
cve_referencegithub.com/lche511/cve/blob/main/Hermes_MCP_Tool_Resource_Amplification_DoS_Report/REPORT.mdunverified⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
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