๐Ÿ” CVE Alert

CVE-2026-48521

MEDIUM 5.9

Envoy: HTTP/3 connection pool selection null-derefs in ProdClusterManagerFactory::allocateConnPool when transport_socket_options is null

CVSS Score
5.9
EPSS Score
0.0%
EPSS Percentile
0th

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.

CWE CWE-476
Vendor envoyproxy
Product envoy
Published Sep 21, 2026
Last Updated Sep 21, 2026
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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Affected Versions

envoyproxy / envoy
< 1.36.10 >= 1.37.0, < 1.37.6 >= 1.38.0, < 1.38.4 >= 1.39.0, < 1.39.1

References

NVD โ†— CVE.org โ†— EPSS Data โ†—
github.com: https://github.com/envoyproxy/envoy/security/advisories/GHSA-5vff-j9p4-38j3 github.com: https://github.com/envoyproxy/envoy/commit/8ef2da8527fcd17388b046c1add4fb47fb5d0868 github.com: https://github.com/envoyproxy/envoy/commit/cec4899acf03cf551f28611a5f32385648d95f96 github.com: https://github.com/envoyproxy/envoy/commit/e7b4839beef7f43594ce8e94c4563c80db04a8a7 github.com: https://github.com/envoyproxy/envoy/commit/f5436f44103fb14cb8ba42a8db0f54a06c98c45a github.com: https://github.com/envoyproxy/envoy/releases/tag/v1.36.10 github.com: https://github.com/envoyproxy/envoy/releases/tag/v1.37.6 github.com: https://github.com/envoyproxy/envoy/releases/tag/v1.38.4 github.com: https://github.com/envoyproxy/envoy/releases/tag/v1.39.1