CVE-2026-10841: IBM WebSphere Application Server HTTP request smuggling

CVE-2026-10841 · Severity: medium · CVSS 4.2 · Published 2026-09-18

IBM WebSphere Application Server (versions 8.5, 9.0, and Liberty) is vulnerable to HTTP request smuggling, a web protocol flaw that allows attackers to inject malicious requests into HTTP traffic. Exploiting this vulnerability could enable cache poisoning, session hijacking, or bypassing security controls on corporate application servers.

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

Quick answers

Is CVE-2026-10841 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-10841 being exploited in the wild.
How severe is CVE-2026-10841?
Medium severity, with a CVSS score of 4.2, published 18 September 2026.
Which products and versions are affected?
IBM WebSphere Application Server 8.5, 9.0; IBM WebSphere Application Server Liberty affected versions.
Is there a fix for CVE-2026-10841?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-10841 attacked?
It is attacked over the network.
Am I affected by CVE-2026-10841?
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

HTTP request smuggling (CWE-444) occurs when inconsistent parsing of HTTP request boundaries between a reverse proxy and backend server allows an attacker to inject additional HTTP requests through a single connection. The vulnerability affects WebSphere 8.5, 9.0, and Liberty variants, exploitable over the network without authentication. An attacker can craft malicious HTTP requests to desynchronize the request stream, potentially leading to unauthorized access, cache poisoning, or credential theft. IBM has published security updates for affected versions.

Affected products

  • IBM WebSphere Application Server 8.5, 9.0
  • IBM WebSphere Application Server Liberty affected versions

Timeline

  • 2026-09-18: disclosed: CVE-2026-10841 published

References

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