CVE-2026-46340

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.

Affected Software

VendorProductVersion RangeStatus
nettynetty>= 4.2.0.Final, < 4.2.15.Finalaffected
nettynetty< 4.1.135.Finalaffected

Weaknesses

  • CWE-770: CWE-770: Allocation of Resources Without Limits or Throttling

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

netty-transport-sctp: Netty-transport-sctp: Denial of Service due to unbounded memory growth from SctpMessage fragments

Additional References

References