Netty: SCTP reassembly nests buffers without bound
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 4 fixed, 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-770.
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.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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| netty | netty | 4.2.0.Final to before 4.2.15.Final; before 4.1.135.Final | 4.2.15.Final, 4.1.135.Final | Patch available | CNA |
| — | io.netty:netty-transport-sctp (Maven) | 4.2.0.Final to before 4.2.15.Final | 4.2.15.Final | Patch available | GHSA-5xrh-qmmq-w6ch |
| — | io.netty:netty-transport-sctp (Maven) | before 4.1.135.Final | 4.1.135.Final | Patch available | GHSA-5xrh-qmmq-w6ch |
- netty Vendornetty Affected 4.2.0.Final to before 4.2.15.Final; before 4.1.135.Final Fixed in 4.2.15.Final, 4.1.135.Final Patch available CNA
- io.netty:netty-transport-sctp (Maven) Vendor— Affected 4.2.0.Final to before 4.2.15.Final Fixed in 4.2.15.Final Patch available GHSA-5xrh-qmmq-w6ch
- io.netty:netty-transport-sctp (Maven) Vendor— Affected before 4.1.135.Final Fixed in 4.1.135.Final Patch available GHSA-5xrh-qmmq-w6ch
Remediation
- Fix · CNA netty (netty) Fixed in 4.2.15.Final, 4.1.135.Final
- Fix · GHSA-5xrh-qmmq-w6ch io.netty:netty-transport-sctp (Maven) Fixed in 4.2.15.Final Advisory →
- Fix · GHSA-5xrh-qmmq-w6ch io.netty:netty-transport-sctp (Maven) Fixed in 4.1.135.Final Advisory →
Red Hat 6 advisories
- RHSA-2026:53806 Released 2026-08-11 · Red Hat rating ImportantRed Hat JBoss Enterprise Application Platform 7.4.25 security update
- Red Hat JBoss Enterprise Application Platform 7.4.25
- RHSA-2026:53646 Released 2026-08-11 · Red Hat rating ImportantRed Hat JBoss Enterprise Application Platform 7.4.25 Security update
- Red Hat JBoss EAP 7.4 ELS for RHEL 9 eap7-activemq-artemis-2.16.0-22.redhat_00057.1.el9eap, eap7-activemq-artemis-cli-2.16.0-22.redhat_00057.1.el9eap, eap7-activemq-artemis-commons-2.16.0-22.redhat_00057.1.el9eap +47
- RHSA-2026:53645 Released 2026-08-11 · Red Hat rating ImportantRed Hat JBoss Enterprise Application Platform 7.4.25 Security update
- Red Hat JBoss EAP 7.4 ELS for RHEL 8 eap7-activemq-artemis-2.16.0-22.redhat_00057.1.el8eap, eap7-activemq-artemis-cli-2.16.0-22.redhat_00057.1.el8eap, eap7-activemq-artemis-commons-2.16.0-22.redhat_00057.1.el8eap +47
Show 3 more Red Hat advisories
- RHSA-2026:53644 Released 2026-08-11 · Red Hat rating ImportantRed Hat JBoss Enterprise Application Platform 7.4.25 security pdate
- Red Hat JBoss EAP 7.4 ELS for RHEL 7 Server eap7-activemq-artemis-2.16.0-22.redhat_00057.1.el7eap, eap7-activemq-artemis-cli-2.16.0-22.redhat_00057.1.el7eap, eap7-activemq-artemis-commons-2.16.0-22.redhat_00057.1.el7eap +47
- RHSA-2026:41951 Released 2026-07-20 · Red Hat rating ImportantRed Hat Data Grid 8.6.2 security update
- Red Hat Data Grid 8.6.2
- RHSA-2026:37390 Released 2026-07-09 · Red Hat rating ImportantRed Hat Build of Apache Camel 4.18.1.P1 for Spring Boot release.
- Red Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Fuse 7 | Affected | No fix planned: Will not fix |
| Red Hat JBoss Enterprise Application Platform 7 | Affected | No fix yet |
| Red Hat Data Grid 8.6.2 | Fixed | RHSA-2026:41951 |
| Red Hat JBoss EAP 7.4 ELS for RHEL 7 Server | Fixed | RHSA-2026:53644 |
| Red Hat JBoss Enterprise Application Platform 7.4.25 | Fixed | RHSA-2026:53806 |
| Red Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16 | Fixed | RHSA-2026:37390 |
Not affected: 4 products
- Red Hat Enterprise Linux AI (RHEL AI) 3
- Red Hat JBoss Enterprise Application Platform 8
- Red Hat JBoss Enterprise Application Platform Expansion Pack
- Red Hat Single Sign-On 7
Timeline
- 2026-10-02 Threatist record created from CVE-2026-46340
- 2026-10-03 Alias added: GHSA-5xrh-qmmq-w6ch
- 2026-10-10 Fix available: Red Hat JBoss Enterprise Application Platform 8.1 · Red Hat
- 2026-10-16 Affected versions changed · Red Hat
- 2026-10-21 Affected versions changed · Red Hat
- 2026-10-22 Affected versions changed · Red Hat
- 2026-10-25 EPSS moved to the below the 50th percentile
- 2026-11-01 Affected versions changed · Red Hat
References
More Netty vulnerabilities
- TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
- TI-2026-30861 Netty: HTTP/1.0 TE+CL Coexistence Bypasses Smuggling Sanitization CVSS 3.1CRITICAL 9.8
- TI-2026-30864 Netty: HttpClientCodec response desynchronization CVSS 3.1CRITICAL 9.1
- TI-2026-30859 Netty: DNS Codec Input Validation Bypass in Netty (Encoder + Decoder) CVSS 3.1CRITICAL 9.1
- TI-2026-40973 Netty: Missing CertificateID Validation in OCSP Response Allows Replay Attacks CVSS 3.1CRITICAL 9.1
- TI-2026-40972 Uncontrolled resource consumption in netty CVSS 3.1HIGH 7.5
Sources
- CVE-2026-46340 · CVE Program
- CVE-2026-46340 · NVD
- FIRST EPSS
- GHSA-5xrh-qmmq-w6ch · GitHub Advisory Database · CC BY 4.0
- CVE-2026-46340 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences