CVE-2026-50020 Security Details

CVE ID

CVE-2026-50020

CWE

CWE-444

CVE Description

Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, before reading the first request-line, `HttpObjectDecoder` skips every byte for which `Character.isISOControl(b)` is `true` (0x00–0x1F and 0x7F) as well as all whitespace. RFC 9112 §2.2 only asks servers to ignore empty CRLF lines preceding the request-line — a carefully scoped robustness allowance intended to handle HTTP/1.0 POST workarounds. Silently absorbing NUL bytes, SOH, STX, and other non-CRLF control characters goes significantly beyond this, and can be exploited for request-boundary confusion in pipelined or multiplexed transports where a front-end component treats those bytes differently. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Published

Jun 15, 2026

CVSS Score & Severity

6.9Medium

CVSS Vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

EPSS Score

0.027%

Malware

malware

KEV Status

Not in KEV Catalog: No known exploits

Vulnerable Methods

io/netty/handler/codec/http/HttpMessageDecoder.skipControlCharacters(Lio/netty/buffer/ByteBuf;)V

JVMVulnerable params: 0

io/netty/handler/codec/http/HttpObjectDecoder$LineParser.skipControlChars(Lio/netty/buffer/ByteBuf;II)Z

JVMVulnerable params: 0

io/netty/handler/codec/http/HttpObjectDecoder.skipControlCharacters(Lio/netty/buffer/ByteBuf;)Z

JVMVulnerable params: 0

Affected Ecosystems

affected

Source

National Vulnerability Database

References

GitHub · netty/nettyPROJECT