CVE-2026-84287 NousResearch hermes-agent Session Chat api_server.py denial of service
Remote attackers can cause denial of service in NousResearch hermes-agent via the Session Chat Interface, with no vendor response or fix available.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-84287?
CVE-2026-84287 is a medium-severity denial of service vulnerability in NousResearch hermes-agent, published on 1 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A flaw has been found in NousResearch hermes-agent 0.18.0. Affected by this issue is some unknown functionality of the file gateway/platforms/api_server.py of the component Session Chat Interface. This manipulation causes denial of service. The attack is possible to be carried out remotely. The exploit has been published and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
Weakness: CWE-404
Which versions are affected by CVE-2026-84287?
How do I fix CVE-2026-84287?
No fix has been published for CVE-2026-84287 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-84287 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-84287 exists.
Sources
Also known as GHSA-fvfr-42vv-wp2g.