NetSight
IP …
high7.5

CVE-2026-45416

Netty is a network application framework for development of protocol servers and clients.

Impact

Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, SslClientHelloHandler.decode() reads the 24-bit TLS handshake length and, when the ClientHello does not fit in the first record, eagerly allocates `ctx.alloc().buffer(handshakeLength)` (line 161). The guard at line 140 is `handshakeLength > maxClientHelloLength && maxClientHelloLength != 0`, and the commonly-used SniHandler/AbstractSniHandler constructors (SniHandler(Mapping), SniHandler(AsyncMapping), AbstractSniHandler()) pass maxClientHelloLength=0 and handshakeTimeoutMillis=0, so the length guard is disabled and no timeout is scheduled. A 16 MiB request exceeds the default pooled chunk size and becomes a huge/unpooled allocation performed immediately. The buffer is retained in the handler until the channel closes. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Affected packages

EcosystemPackageAffectedFixed in
mavenio.netty:netty-handler>= 4.2.0.Final, <= 4.2.14.Final4.2.15.Final

Affected products

VendorProductAffected versions
NettyNetty
before 4.1.135
from 4.2.0 before 4.2.15

Weakness classification

CWE-770

References