Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Envoyproxy | Envoy | < 1.33.11 |
Related Weaknesses (CWE)
References
- https://github.com/envoyproxy/envoy/security/advisories/GHSA-pq33-4jxh-hgm3Vendor Advisory
- https://github.com/envoyproxy/envoy/security/advisories/GHSA-pq33-4jxh-hgm3Vendor Advisory
FAQ
What is CVE-2025-62409?
CVE-2025-62409 is a vulnerability with a CVSS score of 7.5 (HIGH). 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 ...
How severe is CVE-2025-62409?
CVE-2025-62409 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-62409?
Check the references section above for vendor advisories and patch information. Affected products include: Envoyproxy Envoy.