BlackTreeIndependent security intelligenceIBM · WebSphere Application Server
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Fix not verifiedIBM WebSphere Application Server 9.0, and 8.5 and IBM WebSphere Application Server - Liberty 17.0.0.3 through 26.0.0.7 is vulnerable to HTTP Response Smuggling due to improper handling of non-standard HTTP version tokens.
IBM WebSphere Application Server 9.0, and 8.5 and IBM WebSphere Application Server - Liberty 17.0.0.3 through 26.0.0.7 is vulnerable to HTTP Response Smuggling due to improper handling of non-standard HTTP version tokens.
The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
IBM WebSphere Application Server 9.0, and 8.5 and IBM WebSphere Application Server - Liberty 17.0.0.3 through 26.0.0.7 is vulnerable to HTTP Response Smuggling due to improper handling of non-standard HTTP version tokens.
The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling'). The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:NCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
Operational remediation based on structured source evidence.
Published 28 Jul 2026 · Last source change 30 Jul 2026, 03:55 UTC · CWE-444 · Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Core structured fields are present and their contributing authorities are shown above.
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.