Improper Neutralization of Null Byte or NUL Character Affecting envoyproxy/envoy package, versions [1.35.0,1.35.13)[1.36.0,1.36.9)[1.37.0,1.37.5)[1.38.0,1.38.3)


Severity

Recommended
0.0
medium
0
10

CVSS assessment by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
0.21% (12th percentile)

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  • Snyk IDSNYK-UNMANAGED-ENVOYPROXYENVOY-17661092
  • published28 Jun 2026
  • disclosed26 Jun 2026
  • creditUnknown

Introduced: 26 Jun 2026

CVE-2026-47778  (opens in a new tab)
CWE-158  (opens in a new tab)

How to fix?

Upgrade envoyproxy/envoy to version 1.35.13, 1.36.9, 1.37.5, 1.38.3 or higher.

Overview

Affected versions of this package are vulnerable to Improper Neutralization of Null Byte or NUL Character in the DefaultCertValidator::verifySubjectAltName process. An attacker can bypass authentication by presenting a certificate with a dNSName SAN containing an embedded NUL byte, causing the evaluation to prematurely truncate the string and incorrectly validate the certificate.

CVSS Base Scores

version 4.0
version 3.1