CVE-2026-48521

Summary

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.

Affected Software

VendorProductVersion RangeStatus
envoyproxyenvoy< 1.36.10affected
envoyproxyenvoy>= 1.37.0, < 1.37.6affected
envoyproxyenvoy>= 1.38.0, < 1.38.4affected
envoyproxyenvoy>= 1.39.0, < 1.39.1affected

Weaknesses

  • CWE-476: CWE-476: NULL Pointer Dereference

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: no
    • Technical Impact: partial

Additional References

References