What is CVE-2025-62409?

CVE-2025-62409 is a high-severity vulnerability in Envoyproxy Envoy, classified under NULL Pointer Dereference. CVSS score: 7.5/10. Published 2025-10-16.

How severe is CVE-2025-62409?

High severity. CVSS v3 base score is 7.5 out of 10.

NULL pointer dereference in Envoyproxy Envoy

CVE-2025-62409

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.

EPSS: 0.004 (34.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Envoyproxy Envoy — versions >= 1.34.0, < 1.34.9, < 1.33.10, 1.36.0

Weakness classification (CWE)

CWE-476 — NULL Pointer Dereference

References

security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)

Frequently asked questions

What is CVE-2025-62409?: CVE-2025-62409 is a high-severity vulnerability in Envoyproxy Envoy, classified under NULL Pointer Dereference. CVSS score: 7.5/10. Published 2025-10-16.
How severe is CVE-2025-62409?: High severity. CVSS v3 base score is 7.5 out of 10.