CVE-2026-15634: IBM WebSphere Application Server and IBM WebSphere Application Server - Liberty Request Smuggling

Published Sep 14, 2026
·
Updated

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.

Other sources

IBM WebSphere Application Server 9.0, and 8.5 and IBM WebSphere Application Server - Liberty 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.

— IBM

Affected Software

1 affected componentFixes available
IBM CICS TX Advanced<=10.1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade IBM WebSphere Application Server traditional 8.5 to a version that resolves this vulnerability.

    Fixed in 8.5.5.31
  2. Upgrade

    Upgrade IBM WebSphere Application Server traditional 9.0 to a version that resolves this vulnerability.

    Fixed in 9.0.5.29Patch SB0030823
  3. Upgrade

    Upgrade IBM WebSphere Application Server Liberty to a version that resolves this vulnerability.

    Fixed in 26.0.0.9

Event History

Sep 14, 2026
CVE Published
via MITRE·08:01 PM
Data Sourced
via MITRE·08:01 PM
RemedyDescriptionSeverityWeakness
Data Sourced
via NVD·08:16 PM
DescriptionSeverityWeakness
Sep 16, 2026
Data Sourced
via IBM·12:00 AM
DescriptionAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Company

Resources

Contact

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