{"id":"CVE-2026-84289","state":"PUBLISHED","title":"NousResearch hermes-agent MCP Tool mcp_tool.py list_tools memory allocation","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.","publishedAt":"2026-09-01T21:45:09.843Z","updatedAt":"2026-09-02T16:01:57.035Z","severity":{"score":5.3,"label":"Medium","version":"4.0","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","source":"VulDB"},"assigner":"VulDB","products":["NousResearch hermes-agent"],"affected":[{"vendor":"NousResearch","product":"hermes-agent","versions":[{"version":"0.18.0","status":"affected"},{"version":"0.18.1","status":"affected"},{"version":"0.18.2","status":"affected"}],"cpes":["cpe:2.3:a:nousresearch:hermes-agent:*:*:*:*:*:*:*:*"],"modules":["MCP Tool"]}],"references":["https://vuldb.com/vuln/397720","https://vuldb.com/vuln/397720/cti","https://vuldb.com/cve/CVE-2026-84289","https://vuldb.com/submit/882960","https://github.com/lche511/cve/blob/main/Hermes_MCP_Tool_Resource_Amplification_DoS_Report/REPORT.md"],"weaknesses":["CWE-789","CWE-400"],"ingestedAt":"2026-10-29T20:13:15.269Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/84xxx/CVE-2026-84289.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-84289","state":"PUBLISHED","datePublished":"2026-09-01T21:45:09.843Z","dateUpdated":"2026-09-02T16:01:57.035Z","assignerShortName":"VulDB","assignerOrgId":"1af790b2-7ee1-4545-860a-a788eba489b5","dateReserved":"2026-09-01T15:48:59.951Z"},"containers":{"cna":{"title":"NousResearch hermes-agent MCP Tool mcp_tool.py list_tools memory allocation","descriptions":[{"lang":"en","value":"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":[{"vendor":"NousResearch","product":"hermes-agent","versions":[{"version":"0.18.0","status":"affected"},{"version":"0.18.1","status":"affected"},{"version":"0.18.2","status":"affected"}],"cpes":["cpe:2.3:a:nousresearch:hermes-agent:*:*:*:*:*:*:*:*"],"modules":["MCP Tool"]}],"references":[{"url":"https://vuldb.com/vuln/397720","name":"VDB-397720 | NousResearch hermes-agent MCP Tool mcp_tool.py list_tools memory allocation","tags":["vdb-entry","technical-description"]},{"url":"https://vuldb.com/vuln/397720/cti","name":"VDB-397720 | CTI Indicators (IOB, IOC, IOA)","tags":["signature","permissions-required"]},{"url":"https://vuldb.com/cve/CVE-2026-84289","name":"CVE-2026-84289 | CVE Analysis and Report","tags":["third-party-advisory"]},{"url":"https://vuldb.com/submit/882960","name":"Submit #882960 | NousResearch hermes-agent 0.18.0 Denial of Service","tags":["third-party-advisory"]},{"url":"https://github.com/lche511/cve/blob/main/Hermes_MCP_Tool_Resource_Amplification_DoS_Report/REPORT.md","tags":["exploit"]}],"metrics":[{"cvssV4_0":{"version":"4.0","baseScore":5.3,"vectorString":"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","baseSeverity":"MEDIUM"}},{"cvssV3_1":{"version":"3.1","baseScore":4.3,"vectorString":"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","baseSeverity":"MEDIUM"}},{"cvssV3_0":{"version":"3.0","baseScore":4.3,"vectorString":"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","baseSeverity":"MEDIUM"}},{"cvssV2_0":{"version":"2.0","baseScore":4,"vectorString":"AV:N/AC:L/Au:S/C:N/I:N/A:P/E:POC/RL:ND/RC:UR"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-789","type":"CWE","lang":"en","description":"Uncontrolled Memory Allocation"}]},{"descriptions":[{"cweId":"CWE-400","type":"CWE","lang":"en","description":"Resource Consumption"}]}],"providerMetadata":{"shortName":"VulDB","orgId":"1af790b2-7ee1-4545-860a-a788eba489b5","dateUpdated":"2026-09-01T21:45:09.843Z"},"timeline":[{"time":"2026-09-01T00:00:00.000Z","lang":"en","value":"Advisory disclosed"},{"time":"2026-09-01T02:00:00.000Z","lang":"en","value":"VulDB entry created"},{"time":"2026-09-01T17:54:29.000Z","lang":"en","value":"VulDB entry last update"}],"credits":[{"lang":"en","value":"pengguogood (VulDB User)","type":"reporter"},{"lang":"en","value":"VulDB CNA Team","type":"coordinator"}],"x_generator":["VulDB PVTS v202609"]},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-02T13:18:59.141111Z","id":"CVE-2026-84289","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-02T16:01:57.035Z"}}]}}}