CVE-2025-62409High· 7.5▾ TwilightEnvoy 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 …
▾ Twilight zone — High severity, or a signal on a lesser flaw
impact 41.3 · likelihood 0.1 · exploitation 0
Need a working PoC? Pro members can cast a request and our team develops one — it lands right here.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
Last analysed / modified upstream
0.5%
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.
envoy < 1.33.11envoy >= 1.34.0, < 1.34.9envoy >= 1.35.0, < 1.35.5envoy = 1.36.0Upgrade past the affected range:
envoy 1.35.5Connected by shared product, vendor, weakness, or advisory.
CVE-2025-64527Medium· 6.5Envoy is a high-performance edge/middle/service proxy
CVE-2026-48521Medium· 5.9Envoy is an open source edge and service proxy designed for cloud-native applications
CVE-2026-73547High· 7.5Envoy is an open source edge and service proxy designed for cloud-native applications
CVE-2025-62504Medium· 6.5Envoy is an open source edge and service proxy
CVE-2020-8661High· 7.5CNCF Envoy through 1.13.0 may consume excessive amounts of memory when responding internally to pipelined requests.
CVE-2020-8664Medium· 5.3CNCF Envoy through 1.13.0 has incorrect Access Control when using SDS with Combined Validation Context