Bug 2488391 (CVE-2026-45416)

Summary: CVE-2026-45416 netty-handler: Netty: Denial of Service due to eager buffer allocation in TLS handshake
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: aazores, abrianik, anthomas, ant, anujha, aschwart, asoldano, aszczucz, ataylor, avibelli, bbaranow, bbrownin, bgeorges, bmaxwell, boliveir, bstansbe, ccranfor, cescoffi, chfoley, cmah, dandread, dbruscin, dhanak, dkreling, dlofthou, drichtar, drosa, dsimansk, eaguilar, ebaron, ehelms, ehugonne, ewittman, fmariani, fmongiar, ggainey, ggrzybek, gmalinko, gsmet, istudens, ivassile, iweiss, janstey, jkoehler, jmartisk, jmatsuok, jnethert, jolong, jpasqual, jpechane, jraez, jtolenti, juwatts, jwon, kaycoth, kgaikwad, kingland, kvanderr, lphiri, lthon, manderse, mcarlett, mdellweg, mhulan, mnovotny, mosmerov, mposolda, mstipich, msvehla, nipatil, nmoumoul, nwallace, olubyans, osousa, pantinor, parichar, pberan, pcreech, pesilva, pgallagh, pjindal, pmackay, probinso, rchan, rexwhite, rgodfrey, rguimara, rkubis, rmartinc, rruss, rstancel, rstepani, rsvoboda, sausingh, sbiarozk, sdawley, smallamp, ssilvert, sthirugn, sthorger, swoodman, tasato, tcunning, thjenkin, tmalecek, tqvarnst, vdosoudi, vmuzikar, yfang
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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A flaw was found in Netty, a network application framework. A remote attacker can exploit this vulnerability by sending a crafted TLS (Transport Layer Security) ClientHello message. This can lead to an eager allocation of a large memory buffer, causing a Denial of Service (DoS) due to excessive memory consumption. The issue occurs in the `SslClientHelloHandler.decode()` method when processing the TLS handshake length.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-06-12 15:02:08 UTC
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.

Comment 1 errata-xmlrpc 2026-06-17 23:05:38 UTC
This issue has been addressed in the following products:

  Red Hat Build of Apache Camel 3.33 for Quarkus 3.33.2.SP1

Via RHSA-2026:26586 https://access.redhat.com/errata/RHSA-2026:26586

Comment 2 errata-xmlrpc 2026-07-02 00:04:29 UTC
This issue has been addressed in the following products:

  Streams for Apache Kafka 2.9.4

Via RHSA-2026:34608 https://access.redhat.com/errata/RHSA-2026:34608

Comment 5 errata-xmlrpc 2026-07-09 15:29:56 UTC
This issue has been addressed in the following products:

  Red Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16

Via RHSA-2026:37390 https://access.redhat.com/errata/RHSA-2026:37390

Comment 6 errata-xmlrpc 2026-07-20 11:57:54 UTC
This issue has been addressed in the following products:

  Red Hat Data Grid 8.6.2

Via RHSA-2026:41951 https://access.redhat.com/errata/RHSA-2026:41951

Comment 7 errata-xmlrpc 2026-07-29 19:55:00 UTC
This issue has been addressed in the following products:

  Cryostat 4 on RHEL 9

Via RHSA-2026:48151 https://access.redhat.com/errata/RHSA-2026:48151

Comment 8 errata-xmlrpc 2026-08-03 15:40:42 UTC
This issue has been addressed in the following products:

  Red Hat JBoss Enterprise Application Platform 8.1

Via RHSA-2026:49701 https://access.redhat.com/errata/RHSA-2026:49701

Comment 9 errata-xmlrpc 2026-08-03 15:41:31 UTC
This issue has been addressed in the following products:

  Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9
  Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8
  Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 10

Via RHSA-2026:49700 https://access.redhat.com/errata/RHSA-2026:49700

Comment 10 errata-xmlrpc 2026-08-04 14:00:52 UTC
This issue has been addressed in the following products:

  Red Hat JBoss Enterprise Application Platform 8.1

Via RHSA-2026:50085 https://access.redhat.com/errata/RHSA-2026:50085