CVE-2026-48706

Full vulnerability record from the local CVENow database.

Description

Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.34.0 until 1.35.13, 1.36.9, 1.37.5, and 1.38.3, a vulnerability exists in Envoy's TCP StatsD sink (TcpStatsdSink), where the thread-local flusher buffer can be overflowed by exceptionally long statistic names (e.g., >16KiB). During formatting, TcpStatsdSink reserves a single contiguous memory slice of 16KiB (FLUSH_SLICE_SIZE_BYTES). If formatting a single metric exceeds the remaining capacity, the flusher initiates a buffer rotation but incorrectly continues to allocate another fixed 16KiB slice. If an attacker can trigger a statistic name longer than 16KiB—for example, by sending an HTTP or gRPC request with an extremely long request path (:path) that is recorded by the grpc_stats filter configured with stats_for_all_methods: true—the flusher will attempt to copy the metric name using memcpy operations beyond the allocated heap buffer boundaries. This leads to a heap write overflow, which can cause immediate denial-of-service (process crash) or potential remote code execution (RCE). This vulnerability is fixed in 1.35.13, 1.36.9, 1.37.5, and 1.38.3.

Severity

HIGH

CVSS score

7.5 (v3.1)

Vulnerability status

Analyzed

Source identifier

[email protected]

Published

2026-06-26 18:17:00.027000

Last modified

2026-10-25 17:10:00.197000

View original CVE JSON

{
  "id": "CVE-2026-48706",
  "sourceIdentifier": "[email protected]",
  "published": "2026-06-26T18:17:00.027",
  "lastModified": "2026-10-25T17:10:00.197",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.34.0 until 1.35.13, 1.36.9, 1.37.5, and 1.38.3, a vulnerability exists in Envoy's TCP StatsD sink (TcpStatsdSink), where the thread-local flusher buffer can be overflowed by exceptionally long statistic names (e.g., >16KiB). During formatting, TcpStatsdSink reserves a single contiguous memory slice of 16KiB (FLUSH_SLICE_SIZE_BYTES). If formatting a single metric exceeds the remaining capacity, the flusher initiates a buffer rotation but incorrectly continues to allocate another fixed 16KiB slice. If an attacker can trigger a statistic name longer than 16KiB—for example, by sending an HTTP or gRPC request with an extremely long request path (:path) that is recorded by the grpc_stats filter configured with stats_for_all_methods: true—the flusher will attempt to copy the metric name using memcpy operations beyond the allocated heap buffer boundaries. This leads to a heap write overflow, which can cause immediate denial-of-service (process crash) or potential remote code execution (RCE). This vulnerability is fixed in 1.35.13, 1.36.9, 1.37.5, and 1.38.3."
    },
    {
      "lang": "es",
      "value": "Envoy es un proxy de borde y de servicio de código abierto diseñado para aplicaciones nativas de la nube. Desde 1.34.0 hasta 1.35.13, 1.36.9, 1.37.5 y 1.38.3, existe una vulnerabilidad en el sumidero TCP StatsD de Envoy (TcpStatsdSink), donde el búfer de vaciado local del hilo puede ser desbordado por nombres de estadísticas excepcionalmente largos (p. ej., >16KiB). Durante el formateo, TcpStatsdSink reserva una única porción de memoria contigua de 16KiB (FLUSH_SLICE_SIZE_BYTES). Si formatear una única métrica excede la capacidad restante, el vaciador inicia una rotación del búfer pero incorrectamente continúa asignando otra porción fija de 16KiB. Si un atacante puede desencadenar un nombre de estadística más largo que 16KiB -por ejemplo, enviando una solicitud HTTP o gRPC con una ruta de solicitud extremadamente larga (:path) que es registrada por el filtro grpc_stats configurado con stats_for_all_methods: true- el vaciador intentará copiar el nombre de la métrica utilizando operaciones memcpy más allá de los límites del búfer de pila asignado. Esto conduce a un desbordamiento de escritura en la pila, lo que puede causar una denegación de servicio inmediata (caída del proceso) o una potencial ejecución remota de código (RCE). Esta vulnerabilidad está corregida en 1.35.13, 1.36.9, 1.37.5 y 1.38.3."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "envoyproxy",
          "product": "envoy",
          "versions": [
            {
              "version": ">= 1.38.0, < 1.38.3",
              "status": "affected"
            },
            {
              "version": ">= 1.37.0, < 1.37.5",
              "status": "affected"
            },
            {
              "version": ">= 1.36.0, < 1.36.9",
              "status": "affected"
            },
            {
              "version": ">= 1.34.0, < 1.35.13",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 5.9,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 3.6
      },
      {
        "source": "[email protected]",
        "type": "Primary",
        "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": "2026-06-26T19:05:13.902352Z",
          "id": "CVE-2026-48706",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-120"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "1.34.0",
              "versionEndExcluding": "1.35.13",
              "matchCriteriaId": "FCF9A646-8301-48C6-9A3D-F53AFAE75C39"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "1.36.0",
              "versionEndExcluding": "1.36.9",
              "matchCriteriaId": "B1146A14-3C49-48C3-BC2A-1BBB202EBD84"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "1.37.0",
              "versionEndExcluding": "1.37.5",
              "matchCriteriaId": "2057BF79-00D1-4154-9DC0-3F278C72F4E1"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "1.38.0",
              "versionEndExcluding": "1.38.3",
              "matchCriteriaId": "2A218AD4-BF4B-46EA-96D7-3B25B7E71AC8"
            }
          ]
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-7q3f-gwg7-j8g4",
      "source": "[email protected]",
      "tags": [
        "Vendor Advisory",
        "Mitigation"
      ]
    }
  ]
}