CVE-2026-42583

Summary

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Lz4FrameDecoder allocates a ByteBuf of size decompressedLength (up to 32 MB per block) before LZ4 runs. A peer only needs a 21-byte header plus compressedLength payload bytes - 22 bytes if compressedLength == 1 - to force that allocation. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

Affected Software

VendorProductVersion RangeStatus
nettynetty>= 4.2.0.Alpha1, < 4.2.13.Finalaffected
nettynetty< 4.1.133.Finalaffected
io.nettynetty-codec< 4.1.133.Finalaffected
io.nettynetty-codec-compression< 4.2.13.Finalaffected

Weaknesses

  • CWE-400: CWE-400: Uncontrolled Resource Consumption
  • CWE-770: CWE-770: Allocation of Resources Without Limits or Throttling

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: yes
    • Technical Impact: partial

Additional References

References