CVE-2026-47692 Details
Description
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 vulnerability in Envoy Proxy versions 1.34.0 prior to 1.39, specifically in the PROXY Protocol v2 header generator, allows for the emission of Type-Length-Value (TLV) segments that exceed the maximum allowed length of 65,535 bytes. This discrepancy creates a mismatch between the advertised length in the header and the actual bytes transmitted, potentially leading to the smuggling of bytes into the upstream request. The issue arises when the header generator includes 'skipped' TLVs that were not properly accounted for, allowing attacker-controlled data to spill over into the application stream before any Envoy-managed HTTP filters can process it.
Users can upgrade to Envoy versions 1.35.13, 1.36.9, 1.37.5, or 1.38.3 to address this vulnerability.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jun 26, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/envoyproxy/envoy/security/advisories/GHSA-wh36-hm39-mm3r | [email protected] | Vendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-130 | Improper Handling of Length Parameter Inconsistency | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| envoyproxy envoy | >= 1.34.0, < 1.35.13 >= 1.36.0, < 1.36.9 >= 1.37.0, < 1.37.5 >= 1.38.0, < 1.38.3 |
CPE
Remediation
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Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 27, 2026 | Initial Analysis | [email protected] |
| Jun 26, 2026 | CVE Modified | CISA-ADP |
| Jun 26, 2026 | New CVE Received | [email protected] |