# CVE-2026-45416: Netty: SNI handler pre-allocates up to 16 MiB from nine attacker bytes

> CVE-2026-45416: Netty: SNI handler pre-allocates up to 16 MiB from nine attacker bytes. CVSS 7.5 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-45416
Last updated: 2026-09-18T13:18:25Z

- Published: 2026-06-12 14:10 UTC · Updated: 2026-09-18 13:18 UTC · Assigner: GitHub\_M
- CVSS: 7.5 (CVSS 3.1) · Severity: High · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS: 0.92%, 60th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-770

## 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.

## Affected vendors and products

- netty: netty
- Red Hat: Red Hat AMQ Broker 7.13.6
- Red Hat: Red Hat AMQ Broker 7.14.1
- Red Hat: Red Hat AMQ Clients
- Red Hat: Red Hat Build of Apache Camel 3.33 for Quarkus 3.33.2.SP1
- Red Hat: Red Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16
- Red Hat: Red Hat build of Apache Camel 4 for Quarkus 3
- Red Hat: Red Hat build of Apache Camel - HawtIO 4
- Red Hat: Red Hat build of Apicurio Registry 3
- Red Hat: Red Hat build of Debezium 3
- Red Hat: Red Hat Build of Keycloak
- Red Hat: Red Hat Data Grid 8.6.2
- Red Hat: Red Hat Enterprise Linux AI (RHEL AI) 3
- Red Hat: Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 7
- Red Hat: Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 8
- Red Hat: Red Hat JBoss Enterprise Application Platform 8.1.7.GA
- Red Hat: Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 10
- Red Hat: Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8
- Red Hat: Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9
- Red Hat: Streams for Apache Kafka 2.9.4
- Red Hat: Streams for Apache Kafka 3.2.1

## Tracked companies

- [Bitbucket](https://rewindex.com/company/bitbucket.md)
- [Confluence](https://rewindex.com/company/confluence.md)
- [Jira](https://rewindex.com/company/jira.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-45416)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-45416)
- [https://github.com/netty/netty/releases/tag/netty-4.1.135.Final](https://github.com/netty/netty/releases/tag/netty-4.1.135.Final)
- [https://github.com/netty/netty/releases/tag/netty-4.2.15.Final](https://github.com/netty/netty/releases/tag/netty-4.2.15.Final)
- [https://github.com/netty/netty/security/advisories/GHSA-x4gw-5cx5-pgmh](https://github.com/netty/netty/security/advisories/GHSA-x4gw-5cx5-pgmh)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-45416 · Markdown: https://rewindex.com/cve/CVE-2026-45416.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-45416 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T02:16:59.787Z