HTTP Request Smuggling Vulnerability in IBM WebSphere Application Server
CVE-2026-15634

6.5MEDIUM

Key Information:

Vendor

IBM
Status
Websphere Application Server
Websphere Application Server - Liberty
Vendor
CVE Published:
14 September 2026

What is CVE-2026-15634?

IBM WebSphere Application Server versions 8.5 and 9.0, along with the Liberty variant, exhibit a vulnerability that arises from incorrect handling of the HTTP transfer-encoding request header. This flaw enables an attacker to craft malicious HTTP requests, potentially allowing them to poison web caches, circumvent measures provided by web application firewalls, and execute cross-site scripting (XSS) attacks, thus compromising the integrity and security of web applications.

Affected Version(s)

WebSphere Application Server 9.0

WebSphere Application Server 8.5

WebSphere Application Server - Liberty 17.0.0.3 <= 26.0.0.5

References

https://www.ibm.com/support/pages/node/7286610
vendor-advisorypatch
https://www.ibm.com/support/pages/node/7286611
vendor-advisorypatch

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.