PatchSiren cyber security CVE debrief
CVE-2026-53870 NousResearch CVE debrief
The Hermes Agent before version 0.16.0 has a vulnerability that allows local users to access sensitive information due to world-readable file permissions. Specifically, the files 'response_store.db' and 'webhook_subscriptions.json' are created with permissions that allow any local user to read them. This exposure includes conversation history, tool payloads, prompts, and per-route HMAC secrets. The vulnerability has a CVSS score of 6.8, indicating a medium severity level. Users of Hermes Agent should update to version 0.16.0 or later to mitigate this issue.
- Vendor
- NousResearch
- Product
- hermes-agent
- CVSS
- MEDIUM 6.8
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-06-17
- Original CVE updated
- 2026-06-17
- Advisory published
- 2026-06-17
- Advisory updated
- 2026-06-17
Who should care
System administrators and security teams responsible for Hermes Agent installations, especially in multi-user environments, should be aware of this vulnerability. Local users with filesystem access could exploit this issue to gain unauthorized access to sensitive information.
Technical summary
The Hermes Agent, prior to version 0.16.0, creates two files, 'response_store.db' and 'webhook_subscriptions.json', with world-readable permissions (mode 0o644). This allows local users to read these files without requiring special permissions. The files contain sensitive information such as conversation history, tool payloads, prompts, and HMAC secrets. The vulnerability is characterized by a CVSS vector of CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X, resulting in a CVSS score of 6.8, which is classified as medium severity.
Defensive priority
Medium
Recommended defensive actions
- Update Hermes Agent to version 0.16.0 or later to ensure proper file permissions.
- Review and adjust file permissions for existing installations if immediate update is not feasible.
- Monitor Hermes Agent logs and file access for suspicious activity.
- Limit local user access to sensitive directories and files.
- Implement additional security measures such as file access controls and auditing.
- Regularly review and update software dependencies and configurations.
Evidence notes
The information provided is based on the CVE-2026-53870 record and related sources from Vulncheck and NVD. The vulnerability was publicly disclosed on June 17, 2026, and the Hermes Agent team has released a fix in version 0.16.0.
Official resources
CVE-2026-53870 was publicly disclosed on June 17, 2026.