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Vulnerability · Published Jun 26, 2026 · Assigned by GitHub_M

CVE-2026-47220Envoy: Segmentation fault when using %REQUESTED_SERVER_NAME% in log format

High 7.5

In plain English

A high-severity null pointer dereference in envoy from envoyproxy. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 52% of all known vulnerabilities).

Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.7%top 48.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.37.0 until 1.37.5 and 1.38.3, when the %REQUESTED_SERVER_NAME(X:Y)% is used in log format and host related options is specified, like HOST_FIRST, SNI_FIRST, it's possible to crash Envoy when the specified host header is missing in the request headers. This vulnerability is fixed in 1.37.5 and 1.38.3.

Affected products (as reported)

VendorProductVersions
envoyproxy envoy >= 1.38.0, < 1.38.3>= 1.37.0, < 1.37.5

Weakness: CWE-476 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References