CVE-2026-38444

Medium severity, CVSS 6.1. EPSS: 0.4% chance of exploitation in the next 30 days.

osTicket v1.18.3 is vulnerable to Stored Cross-Site Scripting (XSS) via the email From-header display name. The value is extracted without sanitization in include/class.mailparse.php and stored raw in the poster field of ost_thread_entry. When an unauthenticated attacker sends a reply email to an existing ticket from an unregistered address with an XSS payload in the From display name.

Published 2026-08-03. Last modified 2026-08-31.