---
id: CVE-2020-5403
title: >-
  Reactor Netty HttpServer, versions 0.9.3 and 0.9.4, is exposed to a
  URISyntaxException that causes the connection to be closed prematurely instead
  of producing a 400 response.
summary: >-
  Reactor Netty HttpServer, versions 0.9.3 and 0.9.4, is exposed to a
  URISyntaxException that causes the connection to be closed prematurely instead
  of producing a 400 response.
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-20
  - CWE-755
vendor: broadcom
product: reactor_netty
affected:
  - reactor_netty = 0.9.3
  - reactor_netty = 0.9.4
published: '2020-03-03'
updated: '2026-09-04'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2020-5403'
references:
  - url: 'https://pivotal.io/security/cve-2020-5403'
    label: security@pivotal.io
  - url: 'https://pivotal.io/security/cve-2020-5403'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.01146
epssPercentile: 0.65364
ingestedAt: '2026-09-04T19:26:35.298Z'
---

## Overview

Reactor Netty HttpServer, versions 0.9.3 and 0.9.4, is exposed to a URISyntaxException that causes the connection to be closed prematurely instead of producing a 400 response.

## Affected

- `reactor_netty = 0.9.3`
- `reactor_netty = 0.9.4`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.