CVE-2026-46340

The record

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 packages

Related vulnerabilities

• CVE-2026-50560 Netty is a network application framework for development of protocol servers and clients. Also affects netty
• CVE-2026-50020 Netty is a network application framework for development of protocol servers and clients. Also affects netty
• CVE-2026-50011 Netty is a network application framework for development of protocol servers and clients. Also affects netty
• CVE-2026-50010 Netty is a network application framework for development of protocol servers and clients. Also affects netty
• CVE-2026-48043 Netty is a network application framework for development of protocol servers and clients. Also affects netty
• CVE-2026-48059 Netty is a network application framework for development of protocol servers and clients. Also affects netty
• CVE-2026-47691 Netty is a network application framework for development of protocol servers and clients. Also affects netty
• CVE-2026-48006 Netty is a network application framework for development of protocol servers and clients. Also affects netty