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Vulnerabilities

Vulnerability · CVE-2025-62409

Envoy is a cloud-native, open source edge and service proxy.

Published Oct 16, 2025 · catalog updated Oct 16, 2025 · Envoy is a cloud-native,

Last checked Nov 7, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2025-62409. EPSS is 0.46%. Act only if a listed version of Envoy is a cloud-native, is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Envoy is a cloud-native,).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Medium6.6
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.46%
Remediation
Version ranges on file
Affected products
vendor envoyproxy envoy 1.34.0, < 1.34.9

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor envoyproxy envoy 1.34.0, < 1.34.91.34.0, < 1.34.9

How to fix CVE-2025-62409

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2025-62409. EPSS is 0.46%. Act only if a listed version of Envoy is a cloud-native, is installed.

Which versions are affected?

Compare what you have installed with envoyproxy envoy 1.34.0, < 1.34.9 1.34.0, < 1.34.9. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.46%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 16, 2025 · EUVD

    Detected

    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

  2. Oct 16, 2025 · EUVD

    Updated

    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

Sources

  • CVE.orgVulnerability recordCVE-2025-62409

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2025-62409

    30-day exploitation probability 0.46%

    first.org
  • EUVDVulnerability recordEUVD-2025-34820

    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 u

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Nov 7, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSNov 7, 2026
  • CVE.orgOct 26, 2026
  • EUVDOct 26, 2026