CVE-2026-50572: Envoy: ext_authz - RawHttpClientImpl onSuccess 0x0 segfault
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 extauthz 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 Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 1.36.10 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 1.37.6 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 1.38.4 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 1.39.1
Event History
Frequently Asked Questions
Which Envoy deployments are exposed to this issue?
Deployments using the HTTP external-authorization (ext_authz) client are in scope if they run a version earlier than 1.36.10, 1.37.6, 1.38.4, or 1.39.1. The advisory does not establish the same trigger for unrelated filters.
What conditions are needed for exploitation?
A request must be rejected in a way that leaves a stale request callback, followed by processing of the authorization response in RawHttpClientImpl::onSuccess after the callback owner has been destroyed. The resulting use-after-free can crash the Envoy process under production traffic.
What should be done to remediate the issue?
Upgrade Envoy to 1.36.10, 1.37.6, 1.38.4, or 1.39.1, as appropriate for the release line in use.