CVE-2026-48090: Envoyproxy Envoy

Medium severity, CVSS 5.9. EPSS: 0.6% chance of exploitation in the next 30 days.

Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.37.0 until 1.37.5 and 1.38.3, the HTTP OAuth2 filter (envoy.filters.http.oauth2) can leave an in-flight async token exchange attached to a downstream stream that has already been torn down. A late AsyncClient completion can still invoke OAuth2Filter methods that use StreamDecoderFilterCallbacks after that object’s lifetime has ended, causing undefined behavior, worker crashes (availability loss), and use-after-free / invalid-vptr failures under AddressSanitizer. This is a memory-safety / lifetime issue in the data plane, not a trivial config bug. Remote code execution is not claimed here; the primary demonstrated impact is DoS via crash and UB; any further impact would be deployment- and allocator-dependent. This vulnerability is fixed in 1.37.5 and 1.38.3.

Affected products

• Envoyproxy Envoy: from 1.37.0, before 1.37.5 (fixed in 1.37.5); from 1.38.0, before 1.38.3 (fixed in 1.38.3)

Published 2026-06-26. Last modified 2026-07-08.