CVE-2026-53870: Hermes agent Hermes Agent Creates Response_store.db And Vulnerability

MODERATE
Advisory Identifier: GHSA-99f9-j8r3-p853
Share
CVSS 5.5
CWE-276
Published
Advisory Summary

CVE-2026-53870 is a MODERATE (CVSS 5.5) hermes agent creates response_store.db and vulnerability (CWE-276: Incorrect Default Permissions) affecting Hermes agent libraries in the PyPI ecosystem. The issue involves hermes agent creates response_store.db and webhook_subscriptions.json with world-readable permissions (mode 0o644). Remediation is available by upgrading affected packages to version 0.16.0.

CVE-2026-53870 at a Glance

CVE Identifier CVE-2026-53870
GHSA Identifier GHSA-99f9-j8r3-p853
Severity MODERATE
CVSS v3.1 Base Score 5.5
CWE Classification CWE-276: Incorrect Default Permissions
Affected Product Hermes agent
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 5.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N).

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-53870

To remediate this vulnerability, upgrade all affected Hermes agent dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

hermes-agent fixed: 0.16.0 
pip install hermes-agent>=0.16.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show hermes-agent

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-53870, inspect your installed packages using pip:

pip show hermes-agent

Analyze the terminal output to locate any version of Hermes agent in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.16.0), your application is affected.

Note: The pip show hermes-agent command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-276: Incorrect Default Permissions, where during installation, installed file permissions are set to allow anyone to modify those files. In Hermes agent, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

CVE-2026-53870 Affected Hermes agent Versions

1 component(s)
Fixed Versions:
0.16.0
Product / Package Ecosystem Affected Versions Fixed Version
hermes-agent
pypi/hermes-agent
PyPI
< 0.16.0
0.16.0

References

NVD — CVE-2026-53870 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-53870
Hermes agent Source Repository REPOSITORY
https://github.com/NousResearch/hermes-agent/pull/30917
Hermes agent Source Repository REPOSITORY
https://github.com/NousResearch/hermes-agent/pull/31469
Security Fix Commit FIX COMMIT
https://github.com/NousResearch/hermes-agent/commit/3bace071bfadf2d2bec2ee048471a31ec920e3e8
Hermes agent Source Repository REPOSITORY
https://github.com/NousResearch/hermes-agent
Hermes agent Release RELEASE
https://github.com/NousResearch/hermes-agent/releases/tag/v2026.6.5
www.vulncheck.com/advisories/hermes-a... WEB
https://www.vulncheck.com/advisories/hermes-agent-sensitive-file-permission-vulnerability-in-store-files

Frequently Asked Questions

What is CVE-2026-53870?
CVE-2026-53870 is a security vulnerability in Hermes agent involving Hermes Agent creates response_store.db and webhook_subscriptions.json with world-readable permissions (mode 0o644) under CWE-276: Incorrect Default Permissions.
Which Hermes agent versions are affected?
Affected versions include releases prior to 0.16.0 across affected packages: hermes-agent.
What version fixes CVE-2026-53870?
Upgrading to 0.16.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is hermes-agent affected?
Yes, hermes-agent is affected in releases prior to 0.16.0. Upgrade your dependency to 0.16.0 or later.
What is the CVSS score of CVE-2026-53870?
CVE-2026-53870 has a CVSS v3.1 base score of 5.5 (MODERATE) with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
What CWE is associated with CVE-2026-53870?
CVE-2026-53870 is classified under CWE-276: Incorrect Default Permissions (During installation, installed file permissions are set to allow anyone to modify those files.).
How can I check PyPI dependencies for CVE-2026-53870?
Run the dependency tree command: 'pip show hermes-agent'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-99f9-j8r3-p853",
  "modified" : "2026-06-19T14:48:48Z",
  "published" : "2026-06-17T21:34:38Z",
  "aliases" : [ "CVE-2026-53870" ],
  "summary" : "Hermes Agent creates response_store.db and webhook_subscriptions.json with world-readable permissions (mode 0o644)",
  "details" : "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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "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"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "hermes-agent"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.16.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-53870"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/NousResearch/hermes-agent/pull/30917"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/NousResearch/hermes-agent/pull/31469"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/NousResearch/hermes-agent/commit/3bace071bfadf2d2bec2ee048471a31ec920e3e8"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/NousResearch/hermes-agent"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/NousResearch/hermes-agent/releases/tag/v2026.6.5"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/hermes-agent-sensitive-file-permission-vulnerability-in-store-files"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-276" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-19T14:48:48Z",
    "nvd_published_at" : "2026-06-17T19:18:10Z"
  }
}