CVE-2026-100656

Summary

Netty (io.netty:netty-codec-http) contains an unbounded per-connection queue growth flaw in HttpServerCodec. The codec tracks the HTTP method of each still-unanswered pipelined request; the first 32 entries are bit-packed into a single long, but every additional entry is appended to methodOverflowQueue, an ArrayDeque with no size limit and no rejection path. A remote, unauthenticated attacker who pipelines HTTP/1.1 requests on a single connection while withholding reads on their own end (preventing responses from being flushed) can grow this queue without bound, causing unbounded heap growth and denial of service. Affected versions are 4.2.0.Final through 4.2.17.Final and all releases up to and including 4.1.137.Final; the issue is fixed in 4.2.18.Final and 4.1.138.Final.

Affected Software

VendorProductVersion RangeStatus
nettynetty4.2.0.Final < 4.2.18.Finalaffected
nettynetty4.2.18.Finalunaffected
nettynetty0 < 4.1.138.Finalaffected
nettynetty4.1.138.Finalunaffected
nettynetty0 < 4.1.138.Finalaffected
nettynetty4.1.138.Finalunaffected

Weaknesses

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

References