CVE-2026-53870 Hermes Agent < 0.16.0 - Sensitive File Permission Vulnerability in Store Files
Local attackers can read sensitive conversation history and HMAC secrets from Hermes Agent store files due to insecure file permissions.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-53870?
CVE-2026-53870 is a medium-severity vulnerability in NousResearch hermes-agent, published on 17 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Hermes Agent before 0.16.0 creates response_store.db and webhook_subscriptions.json with world-readable permissions (mode 0o644), exposing conversation history and HMAC secrets to local users. Attackers with local filesystem access can read these files directly to obtain sensitive data including conversation history, tool payloads, prompts, and per-route HMAC secrets.
Weakness: CWE-276
Which versions are affected by CVE-2026-53870?
3 open source packages ship an affected version, including hermes-agent.
| Package | Affected | Fixed in |
|---|---|---|
hermes-agent PyPI | All versions | 0.16.0 |
hermes-agent PyPI | All versions | 0.16.0 |
hermes-agent PyPI | All versions | 0.16.0 |
How do I fix CVE-2026-53870?
Upgrade hermes-agent to 0.16.0 or later.
Is CVE-2026-53870 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-53870 exists.
Sources
Also known as GHSA-99f9-j8r3-p853, PYSEC-2026-2511.