CVE-2026-73549

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 Utility::copyInternetAddressAndPort and QUIC client-address paths reconstruct scoped IPv6 addresses through addressAsString and Ipv6Instance. The string includes a percent scope identifier that inet_pton cannot parse, causing an exception or abort. Kernel-provided scoped IPv6 destinations in ORIGINAL_DST transparent-proxy deployments, and affected QUIC connection paths, can therefore terminate the process. The relevant scope boundary is that the HTTP use_http_header override rejects scoped addresses earlier; the advisory's crash path requires a kernel-provided original destination or the affected QUIC path. 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-754: CWE-754: Improper Check for Unusual or Exceptional Conditions

References