HTTP Request Smuggling Affecting envoyproxy/envoy package, versions [,1.36.10)[1.37.0,1.37.6)[1.38.0,1.38.4)[1.39.0,1.39.1)


Severity

Recommended
0.0
high
0
10

CVSS assessment by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
0.48% (39th percentile)

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  • Snyk IDSNYK-UNMANAGED-ENVOYPROXYENVOY-20078991
  • published24 Sept 2026
  • disclosed26 Aug 2026
  • creditUnknown

Introduced: 26 Aug 2026

CVE-2026-73548  (opens in a new tab)
CWE-444  (opens in a new tab)

How to fix?

Upgrade envoyproxy/envoy to version 1.36.10, 1.37.6, 1.38.4, 1.39.1 or higher.

Overview

Affected versions of this package are vulnerable to HTTP Request Smuggling in the connection process. An attacker can gain unauthorized access to sensitive information by sending specially crafted generic non-WebSocket HTTP upgrade requests, which can result in connection poisoning.

CVSS Base Scores

version 4.0
version 3.1