Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Envoyproxy | Envoy | >= 1.37.0, < 1.37.5 |
Related Weaknesses (CWE)
References
- https://github.com/envoyproxy/envoy/security/advisories/GHSA-j9wh-4qfm-wf2vExploitVendor Advisory
- https://access.redhat.com/security/cve/CVE-2026-47220
- https://bugzilla.redhat.com/show_bug.cgi?id=2493652
- https://github.com/envoyproxy/envoy/security/advisories/GHSA-j9wh-4qfm-wf2vExploitVendor Advisory
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-47220.json
FAQ
What is CVE-2026-47220?
CVE-2026-47220 is a vulnerability with a CVSS score of 7.5 (HIGH). 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...
How severe is CVE-2026-47220?
CVE-2026-47220 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-47220?
Check the references section above for vendor advisories and patch information. Affected products include: Envoyproxy Envoy.