In IceWarp Server 12.0.3.1 and before, there is XSS in the /webmail/ username field.
- https://cxsecurity.com/issue/WLB-2018080098
- https://packetstormsecurity.com/files/148887/IceWarp-WebMail-12.0.3.1-Cross-Site-Scripting.html
No PoCs found on GitHub currently.