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.
References
| Link | Resource |
|---|---|
| https://github.com/envoyproxy/envoy/security/advisories/GHSA-mvh9-767w-x47j | Vendor Advisory Exploit Mitigation |
| https://github.com/envoyproxy/envoy/security/advisories/GHSA-mvh9-767w-x47j | Vendor Advisory Exploit Mitigation |
Configurations
Configuration 1 (hide)
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History
29 Jun 2026, 18:21
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://github.com/envoyproxy/envoy/security/advisories/GHSA-mvh9-767w-x47j - Vendor Advisory, Exploit, Mitigation | |
| First Time |
Envoyproxy envoy
Envoyproxy |
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| CPE | cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:* |
27 Jun 2026, 04:17
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://github.com/envoyproxy/envoy/security/advisories/GHSA-mvh9-767w-x47j - |
26 Jun 2026, 19:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-06-26 19:16
Updated : 2026-06-29 18:21
NVD link : CVE-2026-47205
Mitre link : CVE-2026-47205
CVE.ORG link : CVE-2026-47205
JSON object : View
Products Affected
envoyproxy
- envoy
CWE
CWE-416
Use After Free
