CVE-2026-50572: Envoy: ext_authz - RawHttpClientImpl onSuccess 0x0 segfault

Severity: medium (CVSS 5.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-21 · updated 2026-10-05
Weakness: CWE-416

Description

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 HTTP external-authorization client can retain a stale request callback after a request is rejected. When RawHttpClientImpl::onSuccess later processes the authorization response, it can invoke callbacks_ after the callback owner has been destroyed, causing a use-after-free and process crash under production traffic. The relevant scope boundary is that the vulnerable path uses the HTTP ext_authz client; the advisory does not establish the same trigger for unrelated filters. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.

Affected products

envoyproxy envoy: before 1.36.10; from 1.37.0 before 1.37.6; from 1.38.0 before 1.38.4; from 1.39.0 before 1.39.1 — fixed in 1.36.10, 1.37.6, 1.38.4, 1.39.1

How to fix

Upgrade to a fixed version: envoyproxy envoy 1.36.10, 1.37.6, 1.38.4, 1.39.1. Check the vendor advisory for mitigations.

References

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