CVE-2026-75595
CVE-2026-75595 updated by NVD
Summary
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.
Affected packages
| Ecosystem | Package | Affected versions | Fixed versions |
|---|---|---|---|
| Maven | io.netty:netty-handler | — | 4.2.17.Final, 4.1.137.Final |
Remediation: Upgrade to 4.2.17.Final or later.
References
Includes data from the GitHub Advisory Database, licensed under CC-BY 4.0.
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EPSS scores provided by the FIRST.org Exploit Prediction Scoring System.