Upstream information

CVE-2026-73550 at MITRE

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 copies every decoded HTTP/2 Host header value before discarding it when :authority is already present. The discarded value bypasses saveHeader, so its bytes and count are not charged against request header limits. An unauthenticated client can use HPACK indexing to submit many references to a large Host value across a bounded number of streams, forcing extreme header-copy allocation and causing the proxy to be out-of-memory killed. The relevant scope boundary is that the demonstrated amplification uses HTTP/2 HPACK and the duplicate Host discard behavior. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.

SUSE information

Overall state of this security issue: Resolved

This issue is currently rated as having important severity.

No SUSE Bugzilla entries cross referenced.

No SUSE Security Announcements cross referenced.

List of released packages

Product(s) Fixed package version(s) References
openSUSE Tumbleweed
  • istioctl >= 1.30.4-1.1
  • istioctl-bash-completion >= 1.30.4-1.1
  • istioctl-zsh-completion >= 1.30.4-1.1
 Patchnames:
openSUSE-Tumbleweed-2026-11630

SUSE Timeline for this CVE

CVE page created: Sat Aug 29 13:13:25 2026
CVE page last modified: Tue Sep 22 11:44:09 2026