CVE-2026-48090 Envoy HTTP: OAuth2 filter late async token completion after stream teardown (UAF / crash risk)
A use-after-free in the Envoy OAuth2 filter allows remote attackers to cause worker crashes and denial of service via late async token completions.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-48090?
CVE-2026-48090 is a medium-severity use after free vulnerability in Envoyproxy Envoy, published on 26 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-416
Which versions are affected by CVE-2026-48090?
1 open source package ship an affected version, including envoy. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
envoy Bitnami | From 1.37.0 | 1.37.5, 1.38.3 |
Products include Envoyproxy Envoy.
How do I fix CVE-2026-48090?
Upgrade envoy to a fixed version for your release line: 1.37.5 or 1.38.3.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-48090 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-48090 exists.
Other vulnerabilities in Envoyproxy Envoy
Sources
Also known as BIT-envoy-2026-48090, GHSA-3cj2-c63f-q26f.