# CVE-2026-11540: IBM WebSphere Application Server information disclosure in FileTransfer servlet

Source: https://junglewise.ai/threats/cve-2026-11540-ibm-websphere-application-server-9-0-and-8-5-could-allow-a-remote  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-18. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-11540 · Severity: medium · CVSS 5.3 · Published 2026-09-18

IBM WebSphere Application Server is an enterprise Java application platform used to run business-critical web applications. A flaw in the FileTransfer servlet could allow a remote attacker to obtain sensitive information about the server's file system without proper authentication, potentially exposing configuration files, credentials, or other confidential data.

Technologies: [IBM WebSphere Application Server](https://junglewise.ai/threats/technologies/websphere-application-server). Vendors: [IBM](https://junglewise.ai/threats/vendors/ibm).

## Quick answers

**Is CVE-2026-11540 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-11540 being exploited in the wild.

**How severe is CVE-2026-11540?** Medium severity, with a CVSS score of 5.3, published 18 September 2026.

**Which products and versions are affected?** IBM WebSphere Application Server 8.5 before 8.5.5.31, 9.0 before 9.0.5.29.

**Is there a fix for CVE-2026-11540?** 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-2026-11540 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-11540?** Check whether you run IBM WebSphere Application Server 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

CVE-2026-11540 is an information disclosure vulnerability in the FileTransfer servlet component of WebSphere Application Server 8.5 and 9.0 prior to patched versions (8.5.5.31 and 9.0.5.29). The vulnerability allows unauthenticated or remote attackers to access file system information through improper access controls on the servlet endpoint. This is a network-accessible attack with no authentication required, exposing sensitive organizational data.

## Affected products

- IBM WebSphere Application Server 8.5 before 8.5.5.31, 9.0 before 9.0.5.29

## Timeline

- 2026-09-18: disclosed

## References

- [https://www.ibm.com/support/pages/node/7286610](https://www.ibm.com/support/pages/node/7286610)

## Related threats

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