CVE-2026-8474 is a reflected cross-site scripting vulnerability (CWE-79) affecting the login API of StormShield Network Security appliances in specified versions. An attacker can inject malicious scripts that execute on a victim's machine when interacting with the vulnerable login API, potentially compromising session cookies or altering page behavior. The vulnerability affects multiple versions spanning 4.3.x, 4.8.x, and 5.0.x releases. The CVSS 3.1 score is 5.3, reflecting medium severity with network attack vector, low attack complexity, no privileges required, and no user interaction needed. No patch or official fix information is currently available, and the vendor has not provided a remediation level or advisory.

Successful exploitation of this vulnerability could allow an attacker to execute arbitrary scripts in the context of the victim's browser when accessing the login API, which may lead to theft of cookies or other sensitive information and manipulation of page behavior such as redirecting users to malicious websites. There is no indication of impact on confidentiality beyond integrity or availability, and no known active exploitation has been reported.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should exercise caution when interacting with the login API and consider implementing web application firewall rules or input validation controls to mitigate reflected XSS risks. Monitor vendor communications for updates on patches or official mitigations.