CVE-2025-62409
High
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.
SeverityHigh
CVSS7.5
Exploit probability—
Product
Envoy
PublishedOct 16, 2025
First seenOct 16, 2025
Weakness typeCWE-476NULL pointer dereference
How to fix
Update
- envoyproxy envoy1.33.11, 1.34.9, 1.35.5 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| envoyproxy envoy | v < 1.33.11, 1.34.0 ≤ v < 1.34.9, 1.35.0 ≤ v < 1.35.5, 1.36.0 | 1.33.11, 1.34.9, 1.35.5 |
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