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CVE-2026-53869

Full vulnerability record from the local CVENow database.

Description

Hermes Agent before 0.16.0 contains a DNS rebinding vulnerability in WebSocket endpoints that allows remote attackers to bypass Host and Origin validation. FastAPI HTTP middleware does not execute for WebSocket upgrade requests on /api/pty, /api/ws, /api/pub, and /api/events endpoints, enabling attackers to exploit DNS rebinding and inject malicious commands or read terminal output.

Severity
HIGH
CVSS score
8.7 (v4.0)
Vulnerability status
Deferred
Source identifier
Published
2026-06-17 19:18:10.743000
Last modified
2026-10-26 11:10:00.157000
View original CVE JSON
{
  "id": "CVE-2026-53869",
  "sourceIdentifier": "[email protected]",
  "published": "2026-06-17T19:18:10.743",
  "lastModified": "2026-10-26T11:10:00.157",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Hermes Agent before 0.16.0 contains a DNS rebinding vulnerability in WebSocket endpoints that allows remote attackers to bypass Host and Origin validation. FastAPI HTTP middleware does not execute for WebSocket upgrade requests on /api/pty, /api/ws, /api/pub, and /api/events endpoints, enabling attackers to exploit DNS rebinding and inject malicious commands or read terminal output."
    },
    {
      "lang": "es",
      "value": "El Agente Hermes anterior a la versión 0.16.0 contiene una vulnerabilidad de reencuadernación de DNS en los puntos finales de WebSocket que permite a atacantes remotos eludir la validación de Host y Origin. El middleware HTTP de FastAPI no se ejecuta para las solicitudes de actualización de WebSocket en los puntos finales /api/pty, /api/ws, /api/pub y /api/events, lo que permite a los atacantes explotar la reencuadernación de DNS e inyectar comandos maliciosos o leer la salida de la terminal."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "NousResearch",
          "product": "hermes-agent",
          "defaultStatus": "unaffected",
          "repo": "https://github.com/NousResearch/hermes-agent",
          "packageURL": "pkg:pypi/hermes-agent",
          "versions": [
            {
              "version": "0",
              "lessThan": "0.16.0",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "0.16.0",
              "versionType": "semver",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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",
          "baseScore": 8.7,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "vulnAvailabilityImpact": "HIGH",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "subAvailabilityImpact": "NONE",
          "exploitMaturity": "NOT_DEFINED",
          "confidentialityRequirement": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "valueDensity": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-06-18T15:28:51.075482Z",
          "id": "CVE-2026-53869",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-306"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/NousResearch/hermes-agent/commit/d9ec90585cf7616b5972e44cf8d92bb569fc3feb",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/NousResearch/hermes-agent/pull/30221",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/NousResearch/hermes-agent/pull/31685",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/NousResearch/hermes-agent/releases/tag/v2026.6.5",
      "source": "[email protected]"
    },
    {
      "url": "https://www.vulncheck.com/advisories/hermes-agent-dns-rebinding-bypass-via-websocket-endpoints",
      "source": "[email protected]"
    }
  ]
}