CVE-2026-8646: IBM WebSphere Application Server

Critical severity, CVSS 9.1. EPSS: 0.6% chance of exploitation in the next 30 days.

IBM WebSphere Application Server 9.0 and 8.5 and IBM WebSphere Application Server - Liberty 17.0.0.3 through 26.0.0.6 are vulnerable to HTTP request smuggling. A remote attacker could smuggle a specially crafted request to the application server thereby allowing the attacker to bypass security controls, spoof identity, escalate privilege, and expose sensitive information.

Affected products

• IBM WebSphere Application Server: from 8.5.0.0, before 8.5.5.30 (fixed in 8.5.5.30); from 9.0.0.0, before 9.0.5.29 (fixed in 9.0.5.29); from 17.0.0.3, before 26.0.0.7 (fixed in 26.0.0.7)

Published 2026-06-22. Last modified 2026-06-24.