CVE-2026-50020

Publication date 12 June 2026

Last updated 19 June 2026


Ubuntu priority

Cvss 3 Severity Score

5.3 · Medium

Score breakdown

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.

Status

Package Ubuntu Release Status
netty 26.04 LTS resolute
Needs evaluation
25.10 questing
Needs evaluation
24.04 LTS noble
Needs evaluation
22.04 LTS jammy
Needs evaluation
20.04 LTS focal
Needs evaluation
18.04 LTS bionic
Needs evaluation
14.04 LTS trusty
Needs evaluation

Severity score breakdown

CVSS version: CVSS v3.0

Base score 5.3 · Medium

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


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