Medium [CVE-2026-47692] PROXY Protocol v2 header generator emits "skipped" TLVs, causing 65 KB attacker-controlled spillover into the upstream application stream
This medium-severity Red Hat Linux advisory covers CVE-2026-47692 affecting OpenShift Service Mesh 2, OpenShift Service Mesh 3.
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Summary
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. 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. 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. Red Hat severity: Moderate — CVSS 4.8 (CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:C/C:N/I:L/A:L).
Weakness: CWE-130. Affected Red Hat products: OpenShift Service Mesh 2; OpenShift Service Mesh 3.
Red Hat does not currently list a fixing RHSA for this CVE.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · high-confidence parse· fetched 12 days ago·verify at source
- 1.35.13
- 1.36.9
- 1.37.5
- 1.38.3
Official advisory · high-confidence parse· fetched 12 days ago·verify at source
Mitigation checklist
- 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.
Official advisory · high-confidence parse· fetched 12 days ago·verify at source
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