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.
No public exploitation has been reported so far. No distribution fix is listed yet; apply vendor mitigations and monitor.
Recommended action: Track your distribution's security tracker and apply the fix as soon as it ships.
Severity metrics
CVSS 3.1 : 6.1 MEDIUM
Vector: AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Affected & fixed versions by distribution
Versions are the native distribution strings (backport-aware): RHEL/Debian/SUSE backport fixes, so compare with the distro version comparator (dpkg / rpm / vercmp), not the upstream version.
No affected package in the tracked watchlist yet (Debian, Ubuntu, Arch, SUSE, Red Hat...). Triage may still be pending.