CVE-2025-64763
Description
Envoy is a high-performance edge/middle/service proxy. In 1.33.12, 1.34.10, 1.35.6, 1.36.2, and earlier, when Envoy is configured in TCP proxy mode to handle CONNECT requests, it accepts client data before issuing a 2xx response and forwards that data to the upstream TCP connection. If a forwarding proxy upstream from Envoy then responds with a non-2xx status, this can cause a de-synchronized CONNECT tunnel state. By default Envoy continues to allow early CONNECT data to avoid disrupting existing deployments. The envoy.reloadable_features.reject_early_connect_data runtime flag can be set to reject CONNECT requests that send data before a 2xx response when intermediaries upstream from Envoy may reject establishment of a CONNECT tunnel.
How to fix
- envoyproxy envoy1.33.13, 1.34.11, 1.35.7, 1.36.3 or later
- github.com/envoyproxy/envoy1.36.3, 1.35.7, 1.34.11, 1.33.13 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| envoyproxy envoy | v < 1.33.13, 1.34.0 ≤ v < 1.34.11, 1.35.0 ≤ v < 1.35.7, 1.36.0 ≤ v < 1.36.3 | 1.33.13, 1.34.11, 1.35.7, 1.36.3 |
| github.com/envoyproxy/envoyGo | 1.36.0 ≤ v < 1.36.3, 1.35.0 ≤ v < 1.35.7, 1.34.0 ≤ v < 1.34.11, v < 1.33.13 | 1.36.3, 1.35.7, 1.34.11, 1.33.13 |
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