CVE-2026-46340: Netty SCTP Reassembly Nests Buffers Without Vulnerability
HIGHCVE-2026-46340 is a HIGH (CVSS 7.5) sctp reassembly nests buffers without vulnerability (CWE-770: Allocation of Resources Without Limits or Throttling) affecting Netty libraries in the Maven ecosystem. The issue involves sctp reassembly nests buffers without bound. Remediation is available by upgrading affected packages to version 4.2.15.Final, 4.1.135.Final.
CVE-2026-46340 at a Glance
Security Impact
CVSS: 7.5
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).
How to Fix CVE-2026-46340
To remediate this vulnerability, upgrade all affected Netty dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
<dependency>
<groupId>io.netty</groupId>
<artifactId>netty-transport-sctp</artifactId>
<version>4.2.15.Final</version>
</dependency><dependency>
<groupId>io.netty</groupId>
<artifactId>netty-transport-sctp</artifactId>
<version>4.1.135.Final</version>
</dependency>Run the following command in your project directory to verify that all resolved dependencies use the patched release:
mvn dependency:tree -Dincludes=io.nettyHow to Check if You Are Affected
To determine whether your Java application is affected by CVE-2026-46340, inspect your build dependencies using the Maven Dependency Plugin:
mvn dependency:tree -Dincludes=io.nettyAnalyze the terminal output to locate any version of Netty in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.2.15.Final), your application is affected.
Note: The mvn dependency:tree -Dincludes=io.netty command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-770: Allocation of Resources Without Limits or Throttling, where the product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated. In Netty, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-46340 Affected Netty Versions
2 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
io.netty:netty-transport-sctp
|
Maven |
≥ 4.2.0.Final
< 4.2.15.Final
|
4.2.15.Final
|
|
io.netty:netty-transport-sctp
|
Maven |
< 4.1.135.Final
|
4.1.135.Final
|
References
Frequently Asked Questions
What is CVE-2026-46340?
Which Netty versions are affected?
What version fixes CVE-2026-46340?
Is netty-transport-sctp affected?
What is the CVSS score of CVE-2026-46340?
What CWE is associated with CVE-2026-46340?
How can I check Maven dependencies for CVE-2026-46340?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-5xrh-qmmq-w6ch",
"modified" : "2026-06-12T19:29:38Z",
"published" : "2026-06-08T23:02:33Z",
"aliases" : [ "CVE-2026-46340" ],
"summary" : "Netty: SCTP reassembly nests buffers without bound",
"details" : "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.",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Maven",
"name" : "io.netty:netty-transport-sctp"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "4.2.0.Final"
}, {
"fixed" : "4.2.15.Final"
} ]
} ],
"database_specific" : {
"last_known_affected_version_range" : "<= 4.2.14.Final"
}
}, {
"package" : {
"ecosystem" : "Maven",
"name" : "io.netty:netty-transport-sctp"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "4.1.135.Final"
} ]
} ],
"database_specific" : {
"last_known_affected_version_range" : "<= 4.1.134.Final"
}
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/netty/netty/security/advisories/GHSA-5xrh-qmmq-w6ch"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-46340"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/netty/netty"
}, {
"type" : "WEB",
"url" : "https://github.com/netty/netty/releases/tag/netty-4.1.135.Final"
}, {
"type" : "WEB",
"url" : "https://github.com/netty/netty/releases/tag/netty-4.2.15.Final"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-770" ],
"severity" : "HIGH",
"github_reviewed" : true,
"github_reviewed_at" : "2026-06-08T23:02:33Z",
"nvd_published_at" : "2026-06-12T15:16:27Z"
}
}