CVE-2026-84289
mediumA vulnerability was found in NousResearch hermes-agent up to 0.18.2.
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
4.3
4.3 (CVSS v3.1)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L Severity source: NVD CVSS v3.1 (cna@vuldb.com)
Timeline (UTC)
Published: 2026-09-01 22:17
Modified: 2026-09-02 16:17
NVD status: Deferred
Last synced 2 days ago
Verified against the source API 2026-10-27 06:50 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).
Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://github.com/lche511/cve/blob/main/Hermes_MCP_Tool_Resource_Amplification_DoS_Report... cna@vuldb.com
- https://vuldb.com/cve/CVE-2026-84289 cna@vuldb.com
- https://vuldb.com/submit/882960 cna@vuldb.com
- https://vuldb.com/vuln/397720 cna@vuldb.com
- https://vuldb.com/vuln/397720/cti cna@vuldb.com
Data sources
NVD CVE API 2.0 — fetched 2026-10-27 06:50 UTC · record ↗