# CVE-2026-61398: Apache CloudStack improper output encoding in password reset UI

Source: https://junglewise.ai/threats/cve-2026-61398-apache-cloudstack-improper-output-encoding-in-password-reset-ui  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-21. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-61398 · Severity: critical · CVSS 9.1 · Published 2026-08-21

Apache CloudStack is a cloud infrastructure management platform used to deploy and manage virtual machines and cloud services. A flaw in the Instance Reset Password feature of the web interface fails to properly encode user input, allowing attackers to inject malicious code that could compromise administrative accounts or steal credentials from users accessing the UI.

Technologies: [Apache Cloudstack](https://junglewise.ai/threats/technologies/cloudstack). Vendors: [Apache](https://junglewise.ai/threats/vendors/apache).

## Quick answers

**Is CVE-2026-61398 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-61398 being exploited in the wild.

**How severe is CVE-2026-61398?** Critical severity, with a CVSS score of 9.1, published 21 August 2026.

**Which products and versions are affected?** Apache Cloudstack 4.15.1.0 through 4.20.3.0 and 4.21.0.0 through 4.22.1.0.

**Is there a fix for CVE-2026-61398?** A patch was published on 2026-08-21: Fix available in versions 4.20.3.1, 4.22.1.1 and later Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-61398 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-61398?** Check whether you run Apache Cloudstack 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

This is an Improper Encoding or Escaping of Output vulnerability (CWE-116, related to XSS) in Apache CloudStack's web UI affecting the Instance Reset Password functionality. The vulnerability exists because user-controlled input is rendered in the UI without proper encoding or escaping, allowing an attacker to inject arbitrary code. An unauthenticated or low-privileged attacker with network access to the CloudStack management interface could craft a malicious payload to execute JavaScript in the context of an administrator's browser session. Successful exploitation could lead to account hijacking, credential theft, or further infrastructure compromise. Patches are available in versions 4.20.3.1, 4.22.1.1, and later.

## Affected products

- Apache CloudStack 4.15.1.0 through 4.20.3.0 and 4.21.0.0 through 4.22.1.0

## Timeline

- 2026-08-21: disclosed
- 2026-08-21: patched: Fix available in versions 4.20.3.1, 4.22.1.1 and later

## References

- [https://lists.apache.org/thread/g6cwddtjrwbh1d56wjz4cfp3fzfm4kbc](https://lists.apache.org/thread/g6cwddtjrwbh1d56wjz4cfp3fzfm4kbc)

## Related threats

- [Apache CloudStack resource leak in scoped global configuration](https://junglewise.ai/threats/cve-2026-59654-apache-cloudstack-resource-leak-in-scoped-global-configuration)
- [Apache CloudStack certificate validation bypass in SAML authentication](https://junglewise.ai/threats/cve-2026-68745-apache-cloudstack-certificate-validation-bypass-in-saml)
- [Apache CloudStack improper access control in annotation APIs](https://junglewise.ai/threats/cve-2026-66797-apache-cloudstack-improper-access-control-in-annotation-apis)
- [Apache CloudStack improper authorization in project role management](https://junglewise.ai/threats/cve-2026-66722-apache-cloudstack-improper-authorization-in-project-role)
- [Apache CloudStack authorization bypass in host tags listing](https://junglewise.ai/threats/cve-2026-66721-apache-cloudstack-authorization-bypass-in-host-tags-listing)