Is CVE-2026-46340 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-46340 being exploited in the wild.

How severe is CVE-2026-46340?

High severity, with a CVSS score of 7.5, published 12 June 2026.

Which products and versions are affected?

io.netty:netty-transport-sctp (Maven) ECOSYSTEM:introduced=4.2.0.Final,fixed=4.2.15.Final.

Is there a fix for CVE-2026-46340?

Yes. io.netty:netty-transport-sctp (Maven): upgrade to 4.2.15.Final or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-46340 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-46340?

Check whether you run io.netty:netty-transport-sctp (Maven), Netty Project Netty Transport SCTP or Netty Project Transport SCTP at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-46340: Netty memory exhaustion in netty-transport-sctp

CVE-2026-46340 · Severity: high · CVSS 7.5 · Published 2026-06-12

Netty is a widely used networking framework that helps developers build high-performance servers and clients. A vulnerability in its SCTP protocol component allows a remote attacker to crash a server by sending a large number of small, incomplete message fragments. This can lead to a total service outage as the server exhausts its available memory trying to process the malicious data.

Vendors: Maven, Netty Project.

Quick answers

Is CVE-2026-46340 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-46340 being exploited in the wild.
How severe is CVE-2026-46340?: High severity, with a CVSS score of 7.5, published 12 June 2026.
Which products and versions are affected?: io.netty:netty-transport-sctp (Maven) ECOSYSTEM:introduced=4.2.0.Final,fixed=4.2.15.Final.
Is there a fix for CVE-2026-46340?: Yes. io.netty:netty-transport-sctp (Maven): upgrade to 4.2.15.Final or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-46340 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-46340?: Check whether you run io.netty:netty-transport-sctp (Maven), Netty Project Netty Transport SCTP or Netty Project Transport SCTP at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

io.netty:netty-transport-sctp (Maven): upgrade to 4.2.15.Final or later

# set io.netty:netty-transport-sctp to 4.2.15.Final in your pom.xml or build.gradle

Technical details

A resource exhaustion vulnerability exists in the netty-transport-sctp component of the Netty framework. The SCTP message handler fails to limit the number of fragments or total bytes accumulated for incomplete SctpMessages. Specifically, the handler wraps each new fragment into a new CompositeByteBuf, creating an N-deep recursive chain of objects. An unauthenticated remote attacker can exploit this by sending a continuous stream of 1-byte DATA chunks without ever setting the 'complete' flag, leading to unbounded memory consumption and eventual stack overflow or OutOfMemoryError during buffer access. The issue is fixed in versions 4.1.135.Final and 4.2.15.Final by limiting the number of inflight incomplete messages and fragments.

Affected products

Netty netty-transport-sctp < 4.1.135.Final, >= 4.2.0.Final, <= 4.2.14.Final

Identifiers

CVE-2026-46340
GHSA-5xrh-qmmq-w6ch

Timeline

2026-06-02: patched: Fixes released in 4.1.135.Final and 4.2.15.Final
2026-06-05: advisory: GitHub Security Advisory GHSA-5xrh-qmmq-w6ch published
2026-06-12: disclosed: CVE-2026-46340 published to NVD

References

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