What is CVE-2026-59838?

CVE-2026-59838 is a medium-severity vulnerability in Fortinet Fortisiem, classified under Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS). CVSS score: 5.9/10. Published 2026-07-15.

How severe is CVE-2026-59838?

Medium severity. CVSS v3 base score is 5.9 out of 10.

XSS in Fortinet Fortisiem

CVE-2026-59838

A improper neutralization of script-related html tags in a web page (basic xss) vulnerability in Fortinet FortiSIEM 7.4.0, FortiSIEM 7.3.0 through 7.3.4, FortiSIEM 7.2.0 through 7.2.6, FortiSIEM 7.1 all versions, FortiSIEM 7.0 all versions…

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L.

Affected products

Fortinet Fortisiem — versions 7.4.0, 7.3.0, 7.2.0

Weakness classification (CWE)

CWE-80 — Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)

References

psirt@fortinet.com (Vendor Advisory)

Frequently asked questions

What is CVE-2026-59838?: CVE-2026-59838 is a medium-severity vulnerability in Fortinet Fortisiem, classified under Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS). CVSS score: 5.9/10. Published 2026-07-15.
How severe is CVE-2026-59838?: Medium severity. CVSS v3 base score is 5.9 out of 10.