Vulnerability from bitnami_vulndb
Published
2026-06-30 23:39
Modified
2026-07-01 00:07
Summary
Envoy: ext_authz Use-After-Free during Stream Teardown with Per-Route Overrides
Details

Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.36.0 until 1.36.9, 1.37.5, and 1.38.3, a Use-After-Free (UAF) vulnerability leading to a sudden segmentation fault exists in Envoy's ext_authz HTTP filter when processing per-route authorization overrides concurrently with rapid downstream client disconnects. During standard request lifecycles, Envoy instantiates the ext_authz filter with a foundational authorization client object (client_). If a matched route dictates a dynamic per-route HTTP or gRPC authorization service override, the filter generates a localized client. In the vulnerable implementation, this transient client aggressively overwrote the default client_ unique pointer by executing client_ = std::move(per_route_client). When a client rapidly establishes and subsequently tears down a stream (such as rapidly refreshing a protected WebSocket endpoint), the downstream triggers the ConnectionManagerImpl::doDeferredStreamDestroy() -> ActiveStream::onResetStream() lifecycle. Envoy immediately sequences Filter::onDestroy() in an attempt to securely abort dispatched asynchronous authorization check transactions via client_->cancel(). By destructing the default client abruptly during initiateCall, a memory lifecycle misalignment occurs within the async client manager. The stream teardown fails to reliably track and cancel the dynamically bound asynchronous authorization tasks, orchestrating a sequence where a late asynchronous callback from the network evaluates against a heavily destroyed ActiveStream validation span, generating a UAF process crash. This vulnerability is fixed in 1.36.9, 1.37.5, and 1.38.3.

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Bitnami",
        "name": "envoy",
        "purl": "pkg:bitnami/envoy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.36.0"
            },
            {
              "fixed": "1.36.9"
            },
            {
              "introduced": "1.37.0"
            },
            {
              "fixed": "1.37.5"
            },
            {
              "introduced": "1.38.0"
            },
            {
              "fixed": "1.38.3"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "severity": [
        {
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "type": "CVSS_V3"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-47205"
  ],
  "database_specific": {
    "cpes": [
      "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*"
    ],
    "severity": "Medium"
  },
  "details": "Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.36.0 until 1.36.9, 1.37.5, and 1.38.3, a Use-After-Free (UAF) vulnerability leading to a sudden segmentation fault exists in Envoy\u0027s ext_authz HTTP filter when processing per-route authorization overrides concurrently with rapid downstream client disconnects. During standard request lifecycles, Envoy instantiates the ext_authz filter with a foundational authorization client object (client_). If a matched route dictates a dynamic per-route HTTP or gRPC authorization service override, the filter generates a localized client. In the vulnerable implementation, this transient client aggressively overwrote the default client_ unique pointer by executing client_ = std::move(per_route_client). When a client rapidly establishes and subsequently tears down a stream (such as rapidly refreshing a protected WebSocket endpoint), the downstream triggers the ConnectionManagerImpl::doDeferredStreamDestroy() -\u003e ActiveStream::onResetStream() lifecycle. Envoy immediately sequences Filter::onDestroy() in an attempt to securely abort dispatched asynchronous authorization check transactions via client_-\u003ecancel(). By destructing the default client abruptly during initiateCall, a memory lifecycle misalignment occurs within the async client manager. The stream teardown fails to reliably track and cancel the dynamically bound asynchronous authorization tasks, orchestrating a sequence where a late asynchronous callback from the network evaluates against a heavily destroyed ActiveStream validation span, generating a UAF process crash. This vulnerability is fixed in 1.36.9, 1.37.5, and 1.38.3.",
  "id": "BIT-envoy-2026-47205",
  "modified": "2026-07-01T00:07:50.168Z",
  "published": "2026-06-30T23:39:20.226Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-mvh9-767w-x47j"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-47205"
    }
  ],
  "schema_version": "1.6.2",
  "summary": "Envoy: ext_authz Use-After-Free during Stream Teardown with Per-Route Overrides"
}


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