# CVE-2026-11549: IBM WebSphere Application Server virtual host bypass

Source: https://junglewise.ai/threats/cve-2026-11549-ibm-websphere-application-server-and-websphere-application-server  
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-2026-11549 · Severity: medium · CVSS 6.5 · Published 2026-09-18

IBM WebSphere Application Server and WebSphere Application Server Liberty contain a virtual host bypass vulnerability that could allow attackers to circumvent security controls on application servers. This could result in unauthorized access to applications or data that should be restricted to specific virtual hosts.

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

## Quick answers

**Is CVE-2026-11549 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-11549 being exploited in the wild.

**How severe is CVE-2026-11549?** Medium severity, with a CVSS score of 6.5, published 18 September 2026.

**Which products and versions are affected?** IBM WebSphere Application Server; IBM WebSphere Application Server Liberty.

**Is there a fix for CVE-2026-11549?** 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-2026-11549 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-11549?** Check whether you run IBM WebSphere Application Server or IBM WebSphere Application Server Liberty. 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

The vulnerability is a virtual host bypass flaw in IBM WebSphere Application Server and Liberty that allows attackers to bypass virtual host restrictions. The attack is network-accessible and likely requires crafted requests to circumvent hostname-based access controls. A patch or update is available from IBM.

## Affected products

- IBM WebSphere Application Server
- IBM WebSphere Application Server Liberty

## Timeline

- 2026-09-18: disclosed

## References

- [https://www.ibm.com/support/pages/node/7287740](https://www.ibm.com/support/pages/node/7287740)

## Related threats

- [IBM WebSphere Application Server Liberty information disclosure in JMX REST connector](https://junglewise.ai/threats/cve-2026-78636-ibm-websphere-application-server-liberty-17-0-0-3-through-26-0-0)
- [IBM WebSphere Application Server Liberty server-side request forgery in Admin Center](https://junglewise.ai/threats/cve-2026-11547-ibm-websphere-application-server-liberty-17-0-0-3-through-26-0-0)
- [IBM WebSphere Application Server Liberty open redirect](https://junglewise.ai/threats/cve-2026-10844-ibm-websphere-application-server-liberty-17-0-0-3-through-26-0-0)
- [IBM WebSphere Application Server Liberty information disclosure](https://junglewise.ai/threats/cve-2026-108284-ibm-websphere-application-server-liberty-17-0-0-3-through-26-0-0)
- [IBM WebSphere Application Server Liberty information disclosure](https://junglewise.ai/threats/cve-2026-103320-ibm-websphere-application-server-liberty-17-0-0-3-through-26-0-0)