Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-06-26T17:59:38 envoy: Envoy: PROXY Protocol v2 header generator emits "skipped" TLVs, causing 65 KB attacker-controlled spillover into the upstream application stream 4.8 CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:C/C:N/I:L/A:L CWE-130

Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.34.0 until 1.35.13, 1.36.9, 1.37.5, and 1.38.3, PROXY Protocol v2 header generator emits TLVs beyond the maximum length of 65535 bytes, causing a mismatch between bytes written and the length field in the header. This can result in smuggled bytes on the upstream request. This vulnerability is fixed in 1.35.13, 1.36.9, 1.37.5, and 1.38.3.

A flaw was found in Envoy. The PROXY Protocol v2 header generator can emit data beyond the maximum allowed length, leading to a mismatch between the actual bytes sent and the length specified in the header. An attacker on an adjacent network could exploit this to smuggle bytes into upstream requests. This could potentially bypass security mechanisms or lead to unexpected behavior in how requests are processed.

Moderate: Envoy's PROXY Protocol v2 header generator can emit TLVs exceeding the maximum length, leading to a mismatch in bytes written and the header's length field. This flaw allows for up to 65 KB of attacker-controlled data to be smuggled into the upstream request, potentially bypassing security controls or corrupting data. This primarily affects deployments where Envoy is configured to use PROXY Protocol v2. Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability. OpenShift Service Mesh 2 Fix deferred openshift-service-mesh/proxyv2-rhel9 OpenShift Service Mesh 3 Fix deferred openshift-service-mesh/istio-proxyv2-rhel9 https://www.cve.org/CVERecord?id=CVE-2026-47692 https://nvd.nist.gov/vuln/detail/CVE-2026-47692 https://github.com/envoyproxy/envoy/security/advisories/GHSA-wh36-hm39-mm3r