Stormshield’s SNS web administration portal contains a DOM-based Cross‑Site Scripting flaw that enables an attacker to inject a malicious script into a browser by crafting a URL with a malicious payload in a specific parameter. The vulnerability can only be triggered when an authenticated administrator follows the link, causing the script to run within that administrator’s session. The impact is the execution of arbitrary JavaScript in the context of the administrator, which could be used to manipulate the browser environment or deface the interface, but no server-side code execution is reported.

The flaw affects Stormshield Network Security SNS versions 5.1.4 EA and 5.0.10. Any deployment running these releases should verify the installed version and plan an upgrade if the patch has not been applied.

The CVSS score of 6.6 indicates moderate severity. The EPSS score is below 1%, suggesting a low likelihood of exploitation, and it is not listed in the CISA KEV catalog. Exploitation requires an authenticated administrator to click a maliciously crafted link, typically delivered via targeted phishing or social engineering. Unprivileged users cannot trigger the flaw.