CVE-2026-38444

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.

Affected products

Osticket

CVSS 3.1

6.1 MEDIUM

EPSS

0.3% (23th percentile)

Weakness

CWE-79

NVD status

Deferred

Published

2026-08-03