CVE-2026-38446

A stored cross-site scripting (XSS) vulnerability exists in osTicket 1.18.3 due to improper sanitization of the thread entry title field. User-controlled input in the title is stored without adequate HTML escaping and later rendered in multiple staff-facing templates without proper output encoding. An attacker can inject arbitrary JavaScript by submitting a crafted ticket reply or email with a malicious subject line.