CVE-2025-64763
Envoy forwards early CONNECT data in TCP proxy mode
At a glance
- Source
- NVD
- EPSS
- EPSS 0.30 % · percentile 23 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Analyzed
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.
Weaknesses (CWE)
- CWE-693 — Protection Mechanism Failure
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | LOW 3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N | GitHub_M |
| CVSS 3.1 | LOW 3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N | NVD · security-advisories@github.com (Secondary) |
| CVSS 3.1 | MEDIUM 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N | NVD · nvd@nist.gov (Primary) |
Advisories
- GHSA-rj35-4m94-77jh — Envoy forwards early CONNECT data in TCP proxy mode
European references
- ENISA EUVD · EUVD-2025-201099
- GCVE · GCVE-0-2025-64763
Affected configurations (NVD CPE)
cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*< 1.33.13cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*≥ 1.34.0 < 1.34.11cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*≥ 1.35.0 < 1.35.7cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*≥ 1.36.0 < 1.36.3
Affected products
| Product | Versions |
|---|---|
| envoyproxy · envoy | affected >= 1.36.0, <= 1.36.2 ; affected >= 1.35.0, <= 1.35.6 ; affected >= 1.34.0, <= 1.34.10 ; affected <= 1.33.12 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |