SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-38444

osTicket v1.18.3 is vulnerable to Stored Cross-Site Scripting (XSS) via the email From-header display name.

MEDIUM 6.1EPSS 0.30%

Does this matter?

Lower severity and a low EPSS score (0.30%). Track it; it rarely justifies an emergency change on its own.

Description

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.

CVSS 3.1
6.1 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS
0.30% probability · 23th percentile
CISA KEV
Not listed
Weakness
CWE-79
Source
cve@mitre.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.