CVE-2026-15634mediumCWE-444

CVE-2026-15634: medium-severity vulnerability in IBM WebSphere Application Server

IBM WebSphere Application Server and IBM WebSphere Application Server - Liberty Request Smuggling

Published · Updated

Follow this CVE+ Monitor WebSphere Application Server+ Monitor WebSphere Application Server - Liberty

E-mail alert when it lands in KEV, gets a public PoC or its score goes up.

13Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 6.5epss 0.4%
IBM WebSphere Application Server 8.5 and 9.0, and IBM WebSphere Application Server - Liberty 17.0.0.3 through 26.0.0.8 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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Affected products
IBM · WebSphere Application ServerIBM · WebSphere Application Server - Liberty
Related CVEs — IBM WebSphere Application Server

In the same product, most dangerous first.

CVE-2019-4279CRITICALCVE-2019-4279EPSS 79.9%CVE-2020-4450CRITICALCVE-2020-4450EPSS 34.7%CVE-2025-36038CRITICALIBM WebSphere Application Server code executionEPSS 13.3%CVE-2020-4464HIGHCVE-2020-4464EPSS 13.2%CVE-2020-4448CRITICALCVE-2020-4448EPSS 12.5%CVE-2020-4589HIGHCVE-2020-4589EPSS 8.5%