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CVE-2026-58250

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 2.12.8 and 2.11.17, an unauthenticated peer with network access to a leafnode listener with compression enabled could crash the server during the pre-authentication leafnode handshake by sending repeated leafnode INFO protocol messages before authentication and account setup completed. This issue is fixed in versions 2.12.8 and 2.11.17.

Severity
HIGH
CVSS score
7.5 (v3.1)
Vulnerability status
Analyzed
Source identifier
Published
2026-07-08 20:16:54.483000
Last modified
2026-10-25 17:10:00.197000
View original CVE JSON
{
  "id": "CVE-2026-58250",
  "sourceIdentifier": "[email protected]",
  "published": "2026-07-08T20:16:54.483",
  "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 2.12.8 and 2.11.17, an unauthenticated peer with network access to a leafnode listener with compression enabled could crash the server during the pre-authentication leafnode handshake by sending repeated leafnode INFO protocol messages before authentication and account setup completed. This issue is fixed in versions 2.12.8 and 2.11.17."
    },
    {
      "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 las versiones 2.12.8 y 2.11.17, un par no autenticado con acceso de red a un oyente de nodo hoja con compresión habilitada podría bloquear el servidor durante el handshake de nodo hoja previo a la autenticación al enviar mensajes de protocolo INFO de nodo hoja repetidos antes de que la autenticación y la configuración de la cuenta se completaran. Este problema está solucionado en las versiones 2.12.8 y 2.11.17."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "nats-io",
          "product": "nats-server",
          "versions": [
            {
              "version": "< 2.11.17",
              "status": "affected"
            },
            {
              "version": ">= 2.12.0-preview.1, < 2.12.8",
              "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": "2026-07-09T13:33:35.375405Z",
          "id": "CVE-2026-58250",
          "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-476"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:*",
              "versionEndExcluding": "2.11.17",
              "matchCriteriaId": "31B216FA-8691-4074-84FC-947A8B616031"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "2.12.0",
              "versionEndExcluding": "2.12.8",
              "matchCriteriaId": "540D8F95-FC42-4FCA-B219-754895555F2A"
            }
          ]
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/nats-io/nats-server/commit/8dcb26eaea78fdcbe96dbee5986d6019fd5cb94a",
      "source": "[email protected]",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://github.com/nats-io/nats-server/commit/fc5fe39177533e9dbdd651d2458285bfae1dde27",
      "source": "[email protected]",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://github.com/nats-io/nats-server/releases/tag/v2.11.17",
      "source": "[email protected]",
      "tags": [
        "Release Notes"
      ]
    },
    {
      "url": "https://github.com/nats-io/nats-server/releases/tag/v2.12.8",
      "source": "[email protected]",
      "tags": [
        "Release Notes"
      ]
    },
    {
      "url": "https://github.com/nats-io/nats-server/security/advisories/GHSA-3g5q-cfh2-cq67",
      "source": "[email protected]",
      "tags": [
        "Vendor Advisory"
      ]
    }
  ]
}