CVE-2026-47205
Full vulnerability record from the local CVENow database.
Description
Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.36.0 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.
View original CVE JSON
{
"id": "CVE-2026-47205",
"sourceIdentifier": "[email protected]",
"published": "2026-06-26T19:16:40.853",
"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 1.36.0 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."
},
{
"lang": "es",
"value": "Envoy es un proxy de borde y de servicio de código abierto diseñado para aplicaciones nativas de la nube. Desde 1.36.0 hasta 1.36.9, 1.37.5 y 1.38.3, existe una vulnerabilidad de uso después de liberación (UAF) que conduce a un fallo de segmentación repentino en el filtro HTTP ext_authz de Envoy al procesar anulaciones de autorización por ruta concurrentemente con desconexiones rápidas de clientes descendentes. Durante los ciclos de vida de solicitud estándar, Envoy instancia el filtro ext_authz con un objeto cliente de autorización fundamental (client_). Si una ruta coincidente dicta una anulación dinámica del servicio de autorización HTTP o gRPC por ruta, el filtro genera un cliente localizado. En la implementación vulnerable, este cliente transitorio sobrescribió agresivamente el puntero único client_ predeterminado al ejecutar client_ = std::move(per_route_client). Cuando un cliente establece y posteriormente cierra rápidamente un flujo (como al actualizar rápidamente un punto final WebSocket protegido), el descendente activa el ciclo de vida ConnectionManagerImpl::doDeferredStreamDestroy() -> ActiveStream::onResetStream(). Envoy secuencia inmediatamente Filter::onDestroy() en un intento de abortar de forma segura las transacciones de verificación de autorización asíncronas despachadas a través de client_ -> cancel(). Al destruir el cliente predeterminado abruptamente durante initiateCall, se produce un desajuste del ciclo de vida de la memoria dentro del gestor de clientes asíncronos. El cierre del flujo no logra rastrear y cancelar de forma fiable las tareas de autorización asíncronas vinculadas dinámicamente, orquestando una secuencia en la que una devolución de llamada asíncrona tardía de la red se evalúa contra un lapso de validación de ActiveStream fuertemente destruido, generando un fallo de proceso por UAF. Esta vulnerabilidad se corrige en 1.36.9, 1.37.5 y 1.38.3."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "envoyproxy",
"product": "envoy",
"versions": [
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"version": ">= 1.38.0, < 1.38.3",
"status": "affected"
},
{
"version": ">= 1.37.0, < 1.37.5",
"status": "affected"
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{
"version": ">= 1.36.0, < 1.36.9",
"status": "affected"
}
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}
],
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"source": "[email protected]",
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"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
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"timestamp": "2026-06-27T02:54:07.255044Z",
"id": "CVE-2026-47205",
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"weaknesses": [
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"source": "[email protected]",
"type": "Secondary",
"description": [
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"lang": "en",
"value": "CWE-416"
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"references": [
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"source": "[email protected]",
"tags": [
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