FKIE_CVE-2026-48521

Vulnerability from fkie_nvd - Published: 2026-09-21 20:17 - Updated: 2026-09-21 20:17
Severity
5.9 (Medium) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy's ProdClusterManagerFactory::allocateConnPool dereferences transport_socket_options while selecting an HTTP/3 connection pool without first checking whether the pointer is null. LoadBalancerContext implementations used by synthetic, mirror, health-check, and async-client calls can return no transport-socket options. With auto_config and HTTP/3 enabled, routine traffic reaching one of those contexts can crash an Envoy worker. The relevant scope boundary is that the affected branch requires HTTP/3 in the protocol set and a context that supplies no transport-socket options. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.
References
security-advisories@github.comhttps://github.com/envoyproxy/envoy/commit/8ef2da8527fcd17388b046c1add4fb47fb5d0868
security-advisories@github.comhttps://github.com/envoyproxy/envoy/commit/cec4899acf03cf551f28611a5f32385648d95f96
security-advisories@github.comhttps://github.com/envoyproxy/envoy/commit/e7b4839beef7f43594ce8e94c4563c80db04a8a7
security-advisories@github.comhttps://github.com/envoyproxy/envoy/commit/f5436f44103fb14cb8ba42a8db0f54a06c98c45a
security-advisories@github.comhttps://github.com/envoyproxy/envoy/releases/tag/v1.36.10
security-advisories@github.comhttps://github.com/envoyproxy/envoy/releases/tag/v1.37.6
security-advisories@github.comhttps://github.com/envoyproxy/envoy/releases/tag/v1.38.4
security-advisories@github.comhttps://github.com/envoyproxy/envoy/releases/tag/v1.39.1
security-advisories@github.comhttps://github.com/envoyproxy/envoy/security/advisories/GHSA-5vff-j9p4-38j3
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/envoyproxy/envoy/security/advisories/GHSA-5vff-j9p4-38j3
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "envoy",
          "vendor": "envoyproxy",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.36.10"
            },
            {
              "status": "affected",
              "version": "\u003e= 1.37.0, \u003c 1.37.6"
            },
            {
              "status": "affected",
              "version": "\u003e= 1.38.0, \u003c 1.38.4"
            },
            {
              "status": "affected",
              "version": "\u003e= 1.39.0, \u003c 1.39.1"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy\u0027s ProdClusterManagerFactory::allocateConnPool dereferences transport_socket_options while selecting an HTTP/3 connection pool without first checking whether the pointer is null. LoadBalancerContext implementations used by synthetic, mirror, health-check, and async-client calls can return no transport-socket options. With auto_config and HTTP/3 enabled, routine traffic reaching one of those contexts can crash an Envoy worker. The relevant scope boundary is that the affected branch requires HTTP/3 in the protocol set and a context that supplies no transport-socket options. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1."
    }
  ],
  "id": "CVE-2026-48521",
  "lastModified": "2026-09-21T20:17:25.463",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 5.9,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 3.6,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-48521",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-09-21T20:02:39.214503Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-09-21T20:17:25.463",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/envoyproxy/envoy/commit/8ef2da8527fcd17388b046c1add4fb47fb5d0868"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/envoyproxy/envoy/commit/cec4899acf03cf551f28611a5f32385648d95f96"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/envoyproxy/envoy/commit/e7b4839beef7f43594ce8e94c4563c80db04a8a7"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/envoyproxy/envoy/commit/f5436f44103fb14cb8ba42a8db0f54a06c98c45a"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/envoyproxy/envoy/releases/tag/v1.36.10"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/envoyproxy/envoy/releases/tag/v1.37.6"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/envoyproxy/envoy/releases/tag/v1.38.4"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/envoyproxy/envoy/releases/tag/v1.39.1"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-5vff-j9p4-38j3"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-5vff-j9p4-38j3"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}



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