Review reviewCritical

CVE-2026-8646

IBM WebSphere Application Server, WebSphere Application Server - Liberty, websphere application server

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.

CVSS: 9.1
EPSS: 0.34%
CISA KEV: Not listed
Published: 2026.06.23

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.34%

Technical severityCVSS 9.1

Vulnerability overview

Affected product and versions

Product: IBM WebSphere Application Server, WebSphere Application Server - Liberty, websphere application server
Affected versions: 9.0.0, 8.5.0, 17.0.0.3, >= 8.5.0.0 < 8.5.5.30, >= 9.0.0.0 < 9.0.5.29, >= 17.0.0.3 < 26.0.0.7
Fixed versions: 8.5.5.30, 9.0.5.29, 26.0.0.7

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that IBM WebSphere Application Server, WebSphere Application Server - Liberty, websphere application server and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CWE: CWE-444