---
id: CVE-2026-15634
title: >-
  IBM WebSphere Application Server 9.0, and 8.5 and IBM WebSphere Application
  Server - Liberty are vulnerable to HTTP request smuggling, caused by improper
  parsing of the HTTP transfer-encoding request header
summary: >-
  IBM WebSphere Application Server 9.0, and 8.5 and IBM WebSphere Application
  Server - Liberty are vulnerable to HTTP request smuggling, caused by improper
  parsing of the HTTP transfer-encoding request header. By sending a specially
  crafte…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N'
cwe:
  - CWE-444
vendor: IBM
product: WebSphere Application Server
affected:
  - websphere_application_server 9.0
  - websphere_application_server 8.5
published: '2026-09-14'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T19:24:58.293'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-15634'
references:
  - url: 'https://www.ibm.com/support/pages/node/7286610'
    label: psirt@us.ibm.com
tags:
  - nvd
  - cve.org
epss: 0.00252
epssPercentile: 0.14813
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-15T17:21:51.397909Z'
ingestedAt: '2026-09-14T20:14:21.147Z'
---

## Overview

IBM WebSphere Application Server 9.0, and 8.5 and IBM WebSphere Application Server - Liberty are vulnerable to HTTP request smuggling, caused by improper parsing of the HTTP transfer-encoding request header. By sending a specially crafted HTTP transfer-encoding request header, an attacker could exploit this vulnerability to poison the web cache, bypass web application firewall protection, and conduct XSS attacks.

## Remediation

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