5.3
MEDIUM CVSS 3.1
CVE-2026-73549
Envoy - Incomplete fix for CVE-2026-26310: copyInternetAddressAndPort crashes on scoped IPv6 addresses in ORIGINAL_DST clusters
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.

INFO

Published Date :

Sept. 21, 2026, 8:17 p.m.

Last Modified :

Sept. 21, 2026, 8:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-73549 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Envoyproxy envoy
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
Solution
Update Envoy to a fixed version to prevent process termination via address parsing.
  • Update Envoy to version 1.36.10 or later.
  • Update Envoy to version 1.37.6 or later.
  • Update Envoy to version 1.38.4 or later.
  • Update Envoy to version 1.39.1 or later.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-73549 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-73549 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-73549 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-73549 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Sep. 21, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V3.1 AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
    Added CWE CWE-754
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/73xxx/CVE-2026-73549.json">CVE-2026-73549</a>
    Added Reference https://github.com/envoyproxy/envoy/commit/109e5a5b08ad10d99074cefd55a747a16ee64da7
    Added Reference https://github.com/envoyproxy/envoy/commit/59b1744a6cb62746db418ac06fc5e359fd25fdb7
    Added Reference https://github.com/envoyproxy/envoy/commit/6e39f4c94deff7a60d382c2d95883e0ea49ff691
    Added Reference https://github.com/envoyproxy/envoy/commit/ab2dca2d65b079768230a7c3d825afeefa330215
    Added Reference https://github.com/envoyproxy/envoy/releases/tag/v1.36.10
    Added Reference https://github.com/envoyproxy/envoy/releases/tag/v1.37.6
    Added Reference https://github.com/envoyproxy/envoy/releases/tag/v1.38.4
    Added Reference https://github.com/envoyproxy/envoy/releases/tag/v1.39.1
    Added Reference https://github.com/envoyproxy/envoy/security/advisories/GHSA-jp5f-qr64-c9vw
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.