Denial of Service Vulnerability in NousResearch hermes-agent Software
CVE-2026-84288

5.3MEDIUM

Key Information:

Vendor

Nousresearch

Status
Hermes-agent
Vendor
CVE Published:
1 September 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-84288?

A vulnerability has been identified in NousResearch's hermes-agent software, specifically affecting the HermesACPAgent.prompt function located in the acp_adapter/session.py file. This flaw can be exploited by an attacker to cause a denial of service, potentially disrupting the affected service's availability. The vulnerability can be triggered remotely, granting malicious users the ability to incapacitate the service without any local access. Despite attempts to notify the vendor about this issue, there has been no response on their part, leaving users at risk of exploitation.

Affected Version(s)

hermes-agent 0.18.0

hermes-agent 0.18.1

hermes-agent 0.18.2

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-84288 - Proof of Concept

References

https://vuldb.com/vuln/397719
vdb-entrytechnical-description
https://vuldb.com/vuln/397719/cti
signaturepermissions-required
https://vuldb.com/cve/CVE-2026-84288
third-party-advisory

CVSS V4

Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

hackerguopeng (VulDB User)
VulDB CNA Team
.