CVE-2026-15396

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

At a glance

Severity: MEDIUM 6.5
EPSS: EPSS 0.37 % · percentile 30 (2026-10-27)
State: PUBLISHED
Published: 2026-09-14
Updated: 2026-10-22
Assigner: ibm
NVD status: Awaiting Analysis

Description

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.

Scores

Version	Score	Vector	Scored by
CVSS 3.1	MEDIUM 6.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N	ibm
CVSS 3.1	MEDIUM 6.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N	NVD · psirt@us.ibm.com (Secondary)

Weaknesses (CWE)

CWE-444

European references

ENISA EUVD · EUVD-2026-78068
GCVE · GCVE-0-2026-15396

CERT-FR advisories

CERTFR-2026-AVI-1336 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
CERTFR-2026-AVI-1206 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr

Affected products

Product	Versions
IBM · WebSphere Application Server	affected 9.0 ; affected 8.5
IBM · WebSphere Application Server - Liberty	affected 17.0.0.3 ≤ 26.0.0.5

References

Sources

Source	Licence
CVE List (CVEProject cvelistV5)	CVE Program Terms of Use
EPSS (FIRST.org)	FIRST — attribution requested
ENISA EUVD	ENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)	Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feeds	Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD