CVE-2026-48090: Envoy HTTP: OAuth2 filter late async token completion after stream teardown (UAF / crash risk)
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 Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
envoy (HTTP OAuth2 filter: envoy.filters.http.oauth2)to a version that resolves this vulnerability.Fixed in 1.37.5 - Upgrade
Upgrade
envoy (HTTP OAuth2 filter: envoy.filters.http.oauth2)to a version that resolves this vulnerability.Fixed in 1.38.3
Event History
Frequently Asked Questions
What is the severity of CVE-2026-48090?
CVE-2026-48090 has a medium severity rating of 5.9.
How do I fix CVE-2026-48090?
To fix CVE-2026-48090, upgrade Envoy to version 1.37.6 or 1.38.4 or later.
What software is affected by CVE-2026-48090?
CVE-2026-48090 affects versions 1.37.0 to 1.37.5 and 1.38.3 of the Envoy HTTP OAuth2 filter.
What type of vulnerability is CVE-2026-48090?
CVE-2026-48090 is categorized as a Use After Free (UAF) vulnerability.
What issue does CVE-2026-48090 pose?
CVE-2026-48090 can lead to a crash risk due to late asynchronous token completion after stream teardown.