Envoy is a cloud-native, open source edge and service proxy. Envoy exposed an out-of-memory (OOM) vector from the mirror response, since async HTTP client will buffer the response with an unbounded buffer.

Envoy is a cloud-native, open source edge and service proxy. There is a use-after-free in `HttpConnectionManager` (HCM) with `EnvoyQuicServerStream` that can crash Envoy. An attacker can exploit this vulnerability by sending a request without `FIN`, then a `RESET_STREAM` frame, and then after receiving the response, closing the connection.

Envoy is a cloud-native, open source edge and service proxy. Envoyproxy with a Brotli filter can get into an endless loop during decompression of Brotli data with extra input.

Envoy is a cloud-native, open source edge and service proxy. There is a crash at `QuicheDataReader::PeekVarInt62Length()`. It is caused by integer underflow in the `QuicStreamSequencerBuffer::PeekRegion()` implementation.

Envoy is a cloud-native, open source edge and service proxy. A crash was observed in `EnvoyQuicServerStream::OnInitialHeadersComplete()` with following call stack. It is a use-after-free caused by QUICHE continuing push request headers after `StopReading()` being called on the stream. As after `StopReading()`, the HCM's `ActiveStream` might have already be destroyed and any up calls from QUICHE could potentially cause use after free.

Envoy is a cloud-native, open source edge and service proxy. A theoretical request smuggling vulnerability exists through Envoy if a server can be tricked into adding an upgrade header into a response. Per RFC https://www.rfc-editor.org/rfc/rfc7230#section-6.7 a server sends 101 when switching protocols. Envoy incorrectly accepts a 200 response from a server when requesting a protocol upgrade, but 200 does not indicate protocol switch. This opens up the possibility of request smuggling through Envoy if the server can be tricked into adding the upgrade header to the response.