Improper Check for Unusual or Exceptional Conditions Affecting netty package, versions <4.1.138-150200.4.56.1


Severity

Recommended
0.0
high
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.28% (19th percentile)

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  • Snyk IDSNYK-SLES157-NETTY-20305684
  • published30 Sept 2026
  • disclosed29 Sept 2026

Introduced: 29 Sep 2026

NewCVE-2026-75595  (opens in a new tab)
CWE-754  (opens in a new tab)

How to fix?

Upgrade SLES:15.7 netty to version 4.1.138-150200.4.56.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream netty package and not the netty package as distributed by SLES. See How to fix? for SLES:15.7 relevant fixed versions and status.

Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Fina and 4.2.17.Final, io.netty.handler.ssl.SslClientHelloHandler#decode checks the wrong offset before reading the four-byte TLS handshake header, so a ClientHello whose handshake header spans records can cause an IndexOutOfBoundsException and invoke select(ctx, null). This selects the default SslContext instead of the SNI-specific context. In deployments where per-SNI clientAuth=REQUIRE is the sole mutual TLS gate, the default SslContext uses clientAuth=NONE or clientAuth=OPTIONAL, and no application-layer certificate verification exists, an unauthenticated remote attacker can bypass the protected route's mutual TLS requirement. This issue is fixed in versions 4.1.137.Final and 4.2.17.Final.

CVSS Base Scores

version 3.1