Is CVE-2026-15064 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-15064 being exploited in the wild.

How severe is CVE-2026-15064?

High severity, with a CVSS score of 8.7, published 28 July 2026.

Which products and versions are affected?

IBM WebSphere Application Server 9.0.0.0 - 9.0.5.28, 8.5.0.0 - 8.5.5.30; IBM WebSphere Application Server Liberty 17.0.0.3 - 26.0.0.7.

Is there a fix for CVE-2026-15064?

A patch was published on 2026-07-28: Interim fixes released; Fix Packs scheduled for 3Q2026 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-15064 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-15064?

Check whether you run IBM WebSphere Application Server or IBM WebSphere Application Server Liberty at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-15064: IBM WebSphere Application Server HTTP response smuggling

CVE-2026-15064 · Severity: high · CVSS 8.7 · Published 2026-07-28

IBM WebSphere Application Server, a platform used to build and run enterprise applications, is vulnerable to a security flaw that could allow attackers to interfere with web traffic. By sending specially crafted web requests, an attacker could potentially bypass security controls, hijack user sessions, or gain unauthorized access to sensitive data. This issue affects both the traditional version of the server and the lightweight Liberty edition when specific web features are enabled.

Technologies: IBM WebSphere Application Server, IBM WebSphere Application Server Liberty. Vendors: IBM.

Quick answers

Is CVE-2026-15064 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-15064 being exploited in the wild.
How severe is CVE-2026-15064?: High severity, with a CVSS score of 8.7, published 28 July 2026.
Which products and versions are affected?: IBM WebSphere Application Server 9.0.0.0 - 9.0.5.28, 8.5.0.0 - 8.5.5.30; IBM WebSphere Application Server Liberty 17.0.0.3 - 26.0.0.7.
Is there a fix for CVE-2026-15064?: A patch was published on 2026-07-28: Interim fixes released; Fix Packs scheduled for 3Q2026 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-15064 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-15064?: Check whether you run IBM WebSphere Application Server or IBM WebSphere Application Server Liberty at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

IBM WebSphere Application Server (Traditional and Liberty) is vulnerable to HTTP Response Smuggling (CWE-444). The vulnerability stems from the improper handling of non-standard HTTP version tokens within the HTTP channel. An attacker can exploit this by sending specially crafted HTTP requests to the server, potentially leading to the poisoning of web caches or the bypassing of security constraints. This vulnerability is present when servlet features (3.0 through 6.1) are enabled. IBM has released interim fixes (PH72191 and PH72192) and plans to include permanent fixes in upcoming Fix Packs (26.0.0.8, 9.0.5.29, and 8.5.5.31).

Affected products

IBM WebSphere Application Server 9.0.0.0 - 9.0.5.28, 8.5.0.0 - 8.5.5.30
IBM WebSphere Application Server - Liberty 17.0.0.3 - 26.0.0.7

Timeline

2026-07-28: disclosed
2026-07-28: advisory
2026-07-28: patched: Interim fixes released; Fix Packs scheduled for 3Q2026

References

https://www.ibm.com/support/pages/node/7281625

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