Envoy: Segmentation fault when using %REQUESTED_SERVER_NAME% in log format
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.
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describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2026-47220US | — | — | ||
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 for… | ||||
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references
External citations — patches, advisories, analysis.
- https://access.redhat.com/security/cve/CVE-2026-47220WEB
- https://bugzilla.redhat.com/show_bug.cgi?id=2493652WEB
- https://github.com/envoyproxy/envoy/security/advisories/GHSA-j9wh-4qfm-wf2vADVISORY
- https://nvd.nist.gov/vuln/detail/CVE-2026-47220WEB
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-47220.jsonWEB
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