CVE-2026-55833

high

Description

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.

References

https://github.com/netty/netty/security/advisories/GHSA-mvh2-crg5-v77c

https://github.com/netty/netty/releases/tag/netty-4.2.16.Final

https://github.com/netty/netty/releases/tag/netty-4.1.136.Final

https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6

https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b

Details

Source: Mitre, NVD

Published: 2026-07-21

Updated: 2026-07-21

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Severity: High

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity: High