CVE-2025-62409
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-10-16

Last updated on: 2025-10-29

Assigner: GitHub, Inc.

Description
Envoy is a cloud-native, open source edge and service proxy. Prior to 1.36.1, 1.35.5, 1.34.9, and 1.33.10, large requests and responses can potentially trigger TCP connection pool crashes due to flow control management in Envoy. It will happen when the connection is closing but upstream data is still coming, resulting in a buffer watermark callback nullptr reference. The vulnerability impacts TCP proxy and HTTP 1 & 2 mixed use cases based on ALPN. This vulnerability is fixed in 1.36.1, 1.35.5, 1.34.9, and 1.33.10.
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Meta Information
Published
2025-10-16
Last Modified
2025-10-29
Generated
2026-06-16
AI Q&A
2025-10-16
EPSS Evaluated
2026-06-15
NVD
CVE-2025-62409
EUVD
EUVD-2025-34820
Affected Vendors & Products
Showing 4 associated CPEs
Vendor Product Version / Range
envoyproxy envoy to 1.33.11 (exc)
envoyproxy envoy From 1.34.0 (inc) to 1.34.9 (exc)
envoyproxy envoy From 1.35.0 (inc) to 1.35.5 (exc)
envoyproxy envoy 1.36.0
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-476 The product dereferences a pointer that it expects to be valid but is NULL.
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Executive Summary

This vulnerability in Envoy, a cloud-native edge and service proxy, occurs when large requests and responses cause TCP connection pool crashes due to flow control management issues. Specifically, it happens when a connection is closing but upstream data is still arriving, leading to a buffer watermark callback nullptr reference. It affects TCP proxy and HTTP 1 & 2 mixed use cases based on ALPN. The issue is fixed in versions 1.36.1, 1.35.5, 1.34.9, and 1.33.10.

Impact Analysis

The vulnerability can cause TCP connection pool crashes in Envoy when handling large requests and responses, potentially leading to service disruptions or degraded performance in systems relying on Envoy for proxying TCP and HTTP traffic.

Mitigation Strategies

To mitigate this vulnerability, upgrade Envoy to one of the fixed versions: 1.36.1, 1.35.5, 1.34.9, or 1.33.10.

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