CVE-2026-45416: Netty: SNI handler pre-allocates up to 16 MiB from nine attacker bytes
Description
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.
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H · CWE-770
Tracked companies
Mapped from the CVE’s affected-product data, NVD CPE matches, vendor advisories or package feeds. A mapping means the vendor’s software is named, not that its hosted service was exposed.
Status incidents that name it
No tracked status incident names this CVE.
Affected vendors and products
netty: nettyRed Hat: Red Hat AMQ Broker 7.13.6Red Hat: Red Hat AMQ Broker 7.14.1Red Hat: Red Hat AMQ ClientsRed Hat: Red Hat Build of Apache Camel 3.33 for Quarkus 3.33.2.SP1Red Hat: Red Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16Red Hat: Red Hat build of Apache Camel 4 for Quarkus 3Red Hat: Red Hat build of Apache Camel - HawtIO 4Red Hat: Red Hat build of Apicurio Registry 3Red Hat: Red Hat build of Debezium 3Red Hat: Red Hat Build of KeycloakRed Hat: Red Hat Data Grid 8.6.2Red Hat: Red Hat Enterprise Linux AI (RHEL AI) 3Red Hat: Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 7Red Hat: Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 8Red Hat: Red Hat JBoss Enterprise Application Platform 8.1.7.GARed Hat: Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 10Red Hat: Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8Red Hat: Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9Red Hat: Streams for Apache Kafka 2.9.4Red Hat: Streams for Apache Kafka 3.2.1
References
- CVE record on cve.org (opens in new tab)
- NVD entry (opens in new tab)
- github.com/netty/netty/releases/tag/netty-4.1.135.Final (opens in new tab)
- github.com/netty/netty/releases/tag/netty-4.2.15.Final (opens in new tab)
- github.com/netty/netty/security/advisories/GHSA-x4gw-5cx5-pgmh (opens in new tab)
- CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (opens in new tab)
- This product uses data from the NVD API but is not endorsed or certified by the NVD. (opens in new tab)
- Known Exploited Vulnerabilities catalog from CISA. (opens in new tab)
- EPSS scores from FIRST (Exploit Prediction Scoring System). (opens in new tab)