Key Information Vulnerability Title: Advantech WISE-DeviceOn Server < 5.4 Authenticated Stored XSS via devicegroups/ Severity: MEDIUM Date: December 5, 2025 CVE: CVE-2025-34261 CWE: CWE-79 Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') CVSS V4 Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N Description Advantech WISE-DeviceOn Server versions prior to 5.4 contain a stored cross-site scripting (XSS) vulnerability in the /rmm/v1/devicegroups/ endpoint. When an authenticated user creates a device group, the name and description values are stored and later rendered in device group listings without proper HTML sanitization. An attacker can inject malicious script into either field, which is then executed in the browser context of users who view or interact with the affected device group, potentially enabling session compromise and unauthorized actions as the victim. References Advantech Security Advisory DeviceOn Software Download Acknowledgments Alex Williams from Pellera Technologies