HTTP Request Smuggling Vulnerability in IBM WebSphere Application Server
CVE-2026-15396

6.5MEDIUM

Key Information:

Vendor

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

What is CVE-2026-15396?

IBM WebSphere Application Server versions 9.0, 8.5, and Liberty have a vulnerability related to improper parsing of the HTTP transfer-encoding request header. This flaw allows attackers to craft malicious HTTP requests that could lead to web cache poisoning, enabling bypass of web application firewalls and potential cross-site scripting (XSS) attacks. Organizations using these affected versions should take immediate steps to mitigate the risk by applying relevant patches and following security best practices.

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

.