CVE-2026-48090: envoyproxy envoy Use After Free

Vulnerability summary

CVE-2026-48090 is a medium (CVSS 5.9) Use After Free vulnerability in envoyproxy envoy. EPSS estimates a 0.58% chance of exploitation in the next 30 days, higher than 46.9% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 26-06-2026
   PublishedVulnerability first disclosed.
2. 08-07-2026
   Last modifiedVulnerability information updated.

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.

• CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.