CVE-2026-46340

CVE-2026-46340 · Netty: SCTP reassembly nests buffers without bound

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 7.5 · High · EPSS 0.6%

Published

2026-06-12T14:19:48.855Z

Updated

2026-09-18T12:04:51.463Z

Stack: system

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