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CVE-2026-58210

Full vulnerability record from the local CVENow database.

Description

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.3 and 2.12.12, an unauthenticated MQTT client could cause the server to retain large incomplete MQTT CONNECT packets before authentication completed, consuming server memory while the parser waited for the advertised MQTT packet length. This issue is fixed in versions 2.14.3 and 2.12.12.

Severity
HIGH
CVSS score
7.5 (v3.1)
Vulnerability status
Analyzed
Source identifier
Published
2026-07-08 20:16:53.950000
Last modified
2026-10-25 17:10:00.197000
View original CVE JSON
{
  "id": "CVE-2026-58210",
  "sourceIdentifier": "[email protected]",
  "published": "2026-07-08T20:16:53.950",
  "lastModified": "2026-10-25T17:10:00.197",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.3 and 2.12.12, an unauthenticated MQTT client could cause the server to retain large incomplete MQTT CONNECT packets before authentication completed, consuming server memory while the parser waited for the advertised MQTT packet length. This issue is fixed in versions 2.14.3 and 2.12.12."
    },
    {
      "lang": "es",
      "value": "NATS Server es un servidor de alto rendimiento para NATS.io, el sistema de mensajería nativo de la nube y del borde. Antes de 2.14.3 y 2.12.12, un cliente MQTT no autenticado podría causar que el servidor retuviera paquetes MQTT CONNECT grandes e incompletos antes de que la autenticación se completara, consumiendo memoria del servidor mientras el analizador esperaba la longitud del paquete MQTT anunciada. Este problema está solucionado en las versiones 2.14.3 y 2.12.12."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "nats-io",
          "product": "nats-server",
          "versions": [
            {
              "version": "< 2.12.12",
              "status": "affected"
            },
            {
              "version": ">= 2.14.0-RC.1, < 2.14.3",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "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": "2026-07-09T13:29:25.711675Z",
          "id": "CVE-2026-58210",
          "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-400"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:*",
              "versionEndExcluding": "2.12.12",
              "matchCriteriaId": "3662387F-C5A6-478A-94D1-849E3C7E81DB"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "2.14.0",
              "versionEndExcluding": "2.14.3",
              "matchCriteriaId": "9BF70729-64AF-4219-BC35-3C5C042F0595"
            }
          ]
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/nats-io/nats-server/commit/bce9ef39469e610aeddb819194ceb7f7edfc0861",
      "source": "[email protected]",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://github.com/nats-io/nats-server/commit/e016e47bbf70304945f2ae9dc397e4862adefaf5",
      "source": "[email protected]",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://github.com/nats-io/nats-server/releases/tag/v2.12.12",
      "source": "[email protected]",
      "tags": [
        "Release Notes"
      ]
    },
    {
      "url": "https://github.com/nats-io/nats-server/releases/tag/v2.14.3",
      "source": "[email protected]",
      "tags": [
        "Release Notes"
      ]
    },
    {
      "url": "https://github.com/nats-io/nats-server/security/advisories/GHSA-r72h-j7qq-v6qg",
      "source": "[email protected]",
      "tags": [
        "Vendor Advisory"
      ]
    }
  ]
}