CVE-2026-11548

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

Published Sep 18, 2026 CVSS 3.1 · 4.8 Medium EPSS < 1% KEV · Not listed
Description
IBM WebSphere Application Server 8.5 and 9.0, and and IBM WebSphere Application Server - Liberty 17.0.0.3 through 26.0.0.8 are affected by an HTTP request smuggling vulnerability.

Remediation

Vendor Solution

IBM strongly recommends addressing the vulnerabilities now by applying the fix pack(s) listed below. For IBM WebSphere Application Server traditional: For V9.0.0.0 through 9.0.5.28: · Apply Fix Pack 9.0.5.29 https://www.ibm.com/support/pages/node/7285876 (availability September 2026) or later fix pack.  For V8.5.0.0 through 8.5.5.30: · Apply Fix Pack 8.5.5.31 https://www.ibm.com/support/pages/node/7285869 (availability September 2026) or later fix pack.  For IBM WebSphere Application Server Liberty 17.0.0.3 - 26.0.0.8: · Apply Liberty Fix Pack 26.0.0.9 https://www.ibm.com/support/pages/node/7285875 (availability September 2026) or later fix pack.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Description IBM WebSphere Application Server 8.5 and 9.0 are affected by an HTTP request smuggling vulnerability. IBM WebSphere Application Server 8.5 and 9.0, and and IBM WebSphere Application Server - Liberty 17.0.0.3 through 26.0.0.8 are affected by an HTTP request smuggling vulnerability.
Title IBM WebSphere Application Server IBM WebSphere Application Server and IBM WebSphere Application Server - Liberty HTTP Request Smuggling
First Time appeared Ibm websphere Application Server Liberty
CPEs cpe:2.3:a:ibm:websphere_application_server_liberty:17.0.0.3:*:*:*:*:*:*:*
cpe:2.3:a:ibm:websphere_application_server_liberty:26.0.0.8:*:*:*:*:*:*:*
Vendors & Products Ibm websphere Application Server Liberty
References
Type Values Removed Values Added
Description IBM WebSphere Application Server and WebSphere Application Server Liberty are affected by an HTTP request smuggling vulnerability. IBM WebSphere Application Server 8.5 and 9.0 are affected by an HTTP request smuggling vulnerability.
Title Multiple security vulnerabilities may affect IBM WebSphere Liberty that is shipped with IBM CICS TX Advanced. IBM WebSphere Application Server
First Time appeared Ibm websphere Application Server
CPEs cpe:2.3:a:ibm:cics_tx_advanced:10.1.0:*:*:*:*:*:*:*
cpe:2.3:a:ibm:cics_tx_advanced:10.1:*:*:*:*:*:*:*
cpe:2.3:a:ibm:websphere_application_server:8.5.0:*:*:*:*:*:*:*
cpe:2.3:a:ibm:websphere_application_server:8.5:*:*:*:*:*:*:*
cpe:2.3:a:ibm:websphere_application_server:9.0.0:*:*:*:*:*:*:*
cpe:2.3:a:ibm:websphere_application_server:9.0:*:*:*:*:*:*:*
Vendors & Products Ibm websphere Application Server
References
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description IBM WebSphere Application Server and WebSphere Application Server Liberty are affected by an HTTP request smuggling vulnerability.
Title Multiple security vulnerabilities may affect IBM WebSphere Liberty that is shipped with IBM CICS TX Advanced.
First Time appeared Ibm
Ibm cics Tx Advanced
Weaknesses CWE-444
CPEs cpe:2.3:a:ibm:cics_tx_advanced:10.1.0:*:*:*:*:*:*:*
cpe:2.3:a:ibm:cics_tx_advanced:10.1:*:*:*:*:*:*:*
Vendors & Products Ibm
Ibm cics Tx Advanced
References
Metrics cvssV3_1

{'score': 4.8, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
ibm
Published
Updated
Oct 22, 2026, 6:53 PM
Reserved
Jun 8, 2026, 3:23 AM
Status
Awaiting Analysis
Published
Sep 18, 2026, 8:17 PM
Modified
Oct 22, 2026, 7:17 PM