CVE-2026-55833 — Netty SPDY zlib header block continues decoded expansion after maxHeaderSize truncation
Netty is a network application framework for development of protocol servers and clients. Prior to 4.1.136.Final and 4.2.16.Final, Netty SPDY header decoding continues inflating…
Published: 2026-07-20 · CVSS: 7.5 · CVSS 3.1
Netty is a network application framework for development of protocol servers and clients. Prior to 4.1.136.Final and 4.2.16.Final, Netty SPDY header decoding continues inflating zlib-compressed header blocks after the raw header parser has exceeded `maxHeaderSize` and marked the frame truncated in `SpdyFrameCodec`, allowing a remote peer to send a small compressed `HEADERS` block that expands into much larger raw header data and causes compression-amplified CPU and allocation churn. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7