# CVE-2026-20108: Cisco Catalyst SD-WAN Manager XSS in web management interface

Source: https://junglewise.ai/threats/cve-2026-20108-cisco-catalyst-sd-wan-manager-xss-in-web-management-interface  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-03-25. Updated: 2026-06-29  
License: CC BY 4.0 with a link back

CVE-2026-20108 · Severity: medium · CVSS 5.4 · Published 2026-03-25

Cisco Catalyst SD-WAN Manager, a centralized management platform for software-defined networks, contains a security flaw in its web interface. An attacker could trick a logged-in administrator into clicking a malicious link, allowing the attacker to execute unauthorized scripts in the administrator's browser. This could lead to the theft of sensitive session information or unauthorized actions performed on behalf of the user.

Technologies: [Cisco Catalyst SD-WAN Manager](https://junglewise.ai/threats/technologies/catalyst-sd-wan-manager). Vendors: [Cisco](https://junglewise.ai/threats/vendors/cisco).

## Quick answers

**Is CVE-2026-20108 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-20108 being exploited in the wild.

**How severe is CVE-2026-20108?** Medium severity, with a CVSS score of 5.4, published 25 March 2026.

**Which products and versions are affected?** Cisco Catalyst SD-WAN Manager 20.12 through 20.12.5.2, 20.12.6, 20.13, 20.14, 20.15 through 20.15.4.1, 20.16, 20.18 through 20.18.1.

**Is there a fix for CVE-2026-20108?** A patch was published on 2026-03-25: Fixed software releases made available by Cisco Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-20108 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-20108?** Check whether you run Cisco Catalyst SD-WAN Manager 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

A stored or reflected cross-site scripting (XSS) vulnerability exists in the web-based management interface of Cisco Catalyst SD-WAN Manager (formerly vManage). The root cause is insufficient validation of user-supplied input. An attacker with low-privileged credentials can exploit this by persuading a targeted user to click a specially crafted link or visit a malicious page while authenticated to the manager. Successful exploitation allows the attacker to execute arbitrary JavaScript in the context of the victim's browser session, potentially leading to the disclosure of sensitive browser-based information or session hijacking. Cisco has released software updates to address this vulnerability; no workarounds are available.

## Affected products

- Cisco Catalyst SD-WAN Manager 20.12 through 20.12.5.2, 20.12.6, 20.13, 20.14, 20.15 through 20.15.4.1, 20.16, 20.18 through 20.18.1

## Timeline

- 2026-03-25: disclosed: Initial public release of Cisco advisory
- 2026-03-25: patched: Fixed software releases made available by Cisco

## References

- [https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-vmanage-xss-ZqkhP9W9](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-vmanage-xss-ZqkhP9W9)

## Related threats

- [Cisco Catalyst SD-WAN Manager API authentication bypass](https://junglewise.ai/threats/cve-2026-76504-a-vulnerability-in-the-api-session-based-authentication)
- [Cisco Catalyst SD-WAN Manager information disclosure in web interface](https://junglewise.ai/threats/cve-2026-20294-cisco-catalyst-sd-wan-manager-information-disclosure-in-web)
- [Cisco Catalyst SD-WAN Manager arbitrary file write in web UI](https://junglewise.ai/threats/cve-2026-20262-cisco-catalyst-sd-wan-manager-arbitrary-file-write-in-web-ui)
- [Cisco Catalyst SD-WAN Manager privilege escalation in CLI](https://junglewise.ai/threats/cve-2026-20245-cisco-catalyst-sd-wan-manager-privilege-escalation-in-cli)
- [Cisco Catalyst SD-WAN Manager XXE in web UI](https://junglewise.ai/threats/cve-2026-20224-cisco-catalyst-sd-wan-manager-xxe-in-web-ui)