Is CVE-2025-62409 actively exploited?

CVE-2025-62409 has no public evidence of in-the-wild exploitation as of 2025-10-29.

What is the CVSS score for CVE-2025-62409?

CVE-2025-62409 has a CVSS score of 6.6 (MEDIUM severity). Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X.

How do I patch CVE-2025-62409?

Patch guidance is available from envoyproxy security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2025-62409.

CVE-2025-62409 - remediation guidance & executive summary

Q: Which products are affected by CVE-2025-62409?

4 products: envoyproxy envoy, envoyproxy envoy, envoyproxy envoy, envoyproxy envoy.

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 Metrics

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector: network
Complexity: low
Privileges: none
User Action: none
Confidentiality: undefined
Integrity: undefined
Availability: undefined
Weaknesses: CWE-476 · NULL Pointer Dereference

Metadata

Primary Vendor: ENVOYPROXY
Published: 10/16/2025
Last Modified: 10/29/2025
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

envoyproxy : envoyenvoyproxy : envoyenvoyproxy : envoyenvoyproxy : envoy

Remediation Guidance

Executive Summary

Cite this page

CVE-2025-62409. CVEDatabase.com. Retrieved 1 May 2026. https://cvedatabase.com/cve/CVE-2025-62409

View on NIST NVD

CVE-2025-62409 vulnerability