CVE-2026-48521

medium

Description

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 ProdClusterManagerFactory::allocateConnPool dereferences transport_socket_options while selecting an HTTP/3 connection pool without first checking whether the pointer is null. LoadBalancerContext implementations used by synthetic, mirror, health-check, and async-client calls can return no transport-socket options. With auto_config and HTTP/3 enabled, routine traffic reaching one of those contexts can crash an Envoy worker. The relevant scope boundary is that the affected branch requires HTTP/3 in the protocol set and a context that supplies no transport-socket options. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.

References

https://docs.cloud.google.com/support/bulletins/index#gcp-2026-057

https://github.com/envoyproxy/envoy/security/advisories/GHSA-5vff-j9p4-38j3

https://github.com/envoyproxy/envoy/releases/tag/v1.39.1

https://github.com/envoyproxy/envoy/releases/tag/v1.38.4

https://github.com/envoyproxy/envoy/releases/tag/v1.37.6

https://github.com/envoyproxy/envoy/releases/tag/v1.36.10

https://github.com/envoyproxy/envoy/commit/f5436f44103fb14cb8ba42a8db0f54a06c98c45a

https://github.com/envoyproxy/envoy/commit/e7b4839beef7f43594ce8e94c4563c80db04a8a7

https://github.com/envoyproxy/envoy/commit/cec4899acf03cf551f28611a5f32385648d95f96

https://github.com/envoyproxy/envoy/commit/8ef2da8527fcd17388b046c1add4fb47fb5d0868

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-84109

Details

Source: Mitre, NVD

Published: 2026-09-21

Updated: 2026-10-05

Risk Information

CVSS v2

Base Score: 5.4

Vector: CVSS2#AV:N/AC:H/Au:N/C:N/I:N/A:C

Severity: Medium

CVSS v3

Base Score: 5.9

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity: Medium

EPSS

EPSS: 0.00739