--- id: CVE-2026-46340 title: >- Netty is a network application framework for development of protocol servers and clients summary: >- Netty is a network application framework for development of protocol servers and clients. In versions of netty-transport-sctp prior to 4.1.135.Final and 4.2.15.Final, for each non-complete SctpMessage fragment the handler does `fragments… severity: high cvss: 7.5 cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H' cwe: - CWE-770 vendor: netty product: netty affected: - netty < 4.1.135 - 'netty >= 4.2.0, < 4.2.15' patched: - netty 4.2.15 published: '2026-06-12' updated: '2026-09-18' sourceUpdated: '2026-09-18T13:18:27.540' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-46340' references: - url: 'https://github.com/netty/netty/releases/tag/netty-4.1.135.Final' label: security-advisories@github.com - url: 'https://github.com/netty/netty/releases/tag/netty-4.2.15.Final' label: security-advisories@github.com - url: 'https://github.com/netty/netty/security/advisories/GHSA-5xrh-qmmq-w6ch' label: security-advisories@github.com - url: 'https://access.redhat.com/errata/RHSA-2026:37390' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:41951' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:50085' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:53644' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:53645' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:53646' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/security/cve/CVE-2026-46340' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2488388' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-46340.json label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:53806' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://www.cve.org/CVERecord?id=CVE-2026-46340' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-46340' - url: 'https://github.com/advisories/GHSA-5xrh-qmmq-w6ch' tags: - nvd - cve.org - csaf - vex - red-hat - ghsa - maven epss: 0.00606 epssPercentile: 0.47714 aliases: - GHSA-5xrh-qmmq-w6ch ecosystem: maven ssvc: exploitation: none automatable: 'yes' technicalImpact: partial timestamp: '2026-06-12T16:30:59.578272Z' ingestedAt: '2026-07-07T15:41:59.852Z' --- ## Overview Netty is a network application framework for development of protocol servers and clients. In versions of netty-transport-sctp prior to 4.1.135.Final and 4.2.15.Final, for each non-complete SctpMessage fragment the handler does `fragments.put(streamId, Unpooled.wrappedBuffer(frag, byteBuf))`, wrapping the previous accumulator and the new slice into a *new* CompositeByteBuf every time. After N fragments the accumulator is an N-deep chain of composites, each holding references and component arrays; readableBytes()/getBytes() on the final buffer recurse N levels. There is no limit on N, on total bytes, or on the number of streamIdentifiers an attacker can open (each gets its own map entry). A peer that never sets the `complete` flag can grow this structure indefinitely from tiny 1-byte DATA chunks. Versions 4.1.135.Final and 4.2.15.Final patch the issue. ## Affected - `netty < 4.1.135` - `netty >= 4.2.0, < 4.2.15` ## Remediation Upgrade past the affected range: - `netty 4.2.15` ## Package advisory (CVE-2026-46340) Affected packages: - `io.netty:netty-transport-sctp >= 4.2.0.Final, <= 4.2.14.Final` - `io.netty:netty-transport-sctp <= 4.1.134.Final` Patched in: - `io.netty:netty-transport-sctp 4.2.15.Final` - `io.netty:netty-transport-sctp 4.1.135.Final` Source: https://github.com/advisories/GHSA-5xrh-qmmq-w6ch ## Vendor advisories - **RHSA-2026:53644** · Red Hat · fixed in: Red Hat JBoss EAP 7.4 ELS for RHEL 7 Server · released 2026-08-11 · [advisory](https://access.redhat.com/errata/RHSA-2026:53644) - **RHSA-2026:41951** · Red Hat · fixed in: Red Hat Data Grid 8.6.2 · released 2026-07-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:41951) - **RHSA-2026:53806** · Red Hat · fixed in: Red Hat JBoss Enterprise Application Platform 7.4.25 · released 2026-08-11 · [advisory](https://access.redhat.com/errata/RHSA-2026:53806) - **RHSA-2026:50085** · Red Hat · fixed in: Red Hat JBoss Enterprise Application Platform 8.1 · released 2026-08-04 · [advisory](https://access.redhat.com/errata/RHSA-2026:50085) - **RHSA-2026:37390** · Red Hat · fixed in: Red Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16 · released 2026-07-09 · [advisory](https://access.redhat.com/errata/RHSA-2026:37390) - **Red Hat VEX** · Important · affected: Red Hat Fuse 7, Red Hat JBoss Enterprise Application Platform Expansion Pack · no fix planned: Red Hat Fuse 7, Red Hat JBoss Enterprise Application Platform Expansion Pack · updated 2026-09-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-46340.json) - **RHSA-2026:53645** · Red Hat · fixed in: Red Hat JBoss EAP 7.4 ELS for RHEL 8 · released 2026-08-11 · [advisory](https://access.redhat.com/errata/RHSA-2026:53645) - **RHSA-2026:53646** · Red Hat · fixed in: Red Hat JBoss EAP 7.4 ELS for RHEL 9 · released 2026-08-11 · [advisory](https://access.redhat.com/errata/RHSA-2026:53646)