# CVE-2025-62409: ecs-service-connect-agent: Envoy is a cloud-native, open source edge and service proxy

CVE-2025-62409 is fixed in ecs-service-connect-agent on 1 platform by ALAS2023-2025-1357 (version v1.34.4.2-1.amzn2023), released January 7, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2025-62409
- Priority: High
- CVSS: n/a (important)
- EPSS: 0.0046
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jan 7, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | ecs-service-connect-agent amzn 2023 | v1.34.4.2-1.amzn2023 | [ALAS2023-2025-1357](https://patchblox.com/security/data/fix/linux/alas2023-2025-1357.md) | Jan 7, 2026 |

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Data as of 2026-11-11T13:47:35Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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