CVE-2026-73549

Envoy - Incomplete fix for CVE-2026-26310: copyInternetAddressAndPort crashes on scoped IPv6 addresses in ORIGINAL_DST clusters

Published: Sep 21, 2026Updated: Sep 23, 2026 Sources: CVE List NVDCWE-754

5.3MEDIUM

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 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.

No summary for this CVE yet.

CVSS Vector Breakdown

Exploitability

AV:NAttack Vector

Network

AC:HAttack Complexity

High

PR:LPrivileges Required

Low

UI:NUser Interaction

None

Scope

S:UScope

Unchanged

Impact

C:NConfidentiality

None

I:NIntegrity

None

A:HAvailability

High

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Weaknesses

CWE-754

Affected Products

envoyproxy

oss-project·USaka envoy, envoy proxy

envoyOn-prem

Cloud & SaaS / api-gateway

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

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References

https://github.com/envoyproxy/envoy/commit/109e5a5b08ad10d99074cefd55a747a16ee64da7

github.com

https://github.com/envoyproxy/envoy/commit/59b1744a6cb62746db418ac06fc5e359fd25fdb7

github.com

https://github.com/envoyproxy/envoy/commit/6e39f4c94deff7a60d382c2d95883e0ea49ff691

github.com

and 6 more references View all →

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