# CVE-2026-16186: IBM WebSphere Application Server reflected cross-site scripting

Source: https://junglewise.ai/threats/cve-2026-16186-ibm-websphere-application-server-reflected-cross-site-scripting  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-14. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-16186 · Severity: medium · CVSS 5.4 · Published 2026-09-14

IBM WebSphere Application Server is a Java-based middleware platform used to host enterprise applications. A reflected cross-site scripting vulnerability allows attackers to inject malicious scripts into web pages viewed by users, potentially stealing session tokens, credentials, or sensitive data displayed on the page.

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-2026-16186 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-16186 being exploited in the wild.

**How severe is CVE-2026-16186?** Medium severity, with a CVSS score of 5.4, published 14 September 2026.

**Which products and versions are affected?** IBM WebSphere Application Server 8.5, 9.0 (fixed in 8.5.5.31 and 9.0.5.29).

**Is there a fix for CVE-2026-16186?** 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-2026-16186 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-16186?** 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-2026-16186 is a reflected cross-site scripting (XSS) vulnerability in IBM WebSphere Application Server versions 8.5 and 9.0. The vulnerability allows an attacker to inject malicious JavaScript code into HTTP requests that gets reflected back to victims in the application's response without proper sanitization. This attack requires user interaction—a victim must visit a malicious link or be redirected to a crafted URL. Patches are available in WebSphere Application Server 8.5.5.31 and later, and 9.0.5.29 and later.

## Affected products

- IBM WebSphere Application Server 8.5, 9.0 (fixed in 8.5.5.31 and 9.0.5.29)

## Timeline

- 2026-09-14: disclosed

## References

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

## Related threats

- [IBM WebSphere Application Server insecure deserialization in messaging](https://junglewise.ai/threats/cve-2026-105442-ibm-websphere-application-server-8-5-and-9-0-and-ibm-websphere)
- [IBM WebSphere Application Server cryptographic signature verification bypass](https://junglewise.ai/threats/cve-2026-101294-ibm-websphere-application-server-liberty-17-0-0-3-through-26-0-0)
- [IBM WebSphere Application Server authorization bypass in authentication](https://junglewise.ai/threats/cve-2026-95680-ibm-websphere-application-server-8-5-and-9-0-could-allow-an)
- [IBM WebSphere Application Server authentication bypass in CSIv2](https://junglewise.ai/threats/cve-2026-93907-ibm-websphere-application-server-8-5-and-9-0-could-allow-a-remote)
- [IBM WebSphere Application Server denial of service via resource consumption](https://junglewise.ai/threats/cve-2026-103499-ibm-websphere-application-server-liberty-17-0-0-3-through-26-0-0)