What is CVE-2026-3862?

CVE-2026-3862 is a medium-severity vulnerability in Broadcom Siteminder, classified under Cross-site Scripting. CVSS score: 4.8/10. Published 2026-03-10.

How severe is CVE-2026-3862?

Medium severity. CVSS v3 base score is 4.8 out of 10.

XSS in Broadcom Siteminder

CVE-2026-3862

Cross-site Scripting (XSS) allows an attacker to submit specially crafted data to the application which is returned unaltered in the resulting web page.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2026-03-10 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (13.8th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 14th percentile — 13.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.001

Affected products

Broadcom Siteminder — versions 12.9, 12.8.x
Broadcom Symantec Siteminder — versions 12.9

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

support.broadcom.com/web/ecx/support-content-notification/-/external/content/Se… (Permissions Required, vendor-advisory)

Frequently asked questions

What is CVE-2026-3862?: CVE-2026-3862 is a medium-severity vulnerability in Broadcom Siteminder, classified under Cross-site Scripting. CVSS score: 4.8/10. Published 2026-03-10.
How severe is CVE-2026-3862?: Medium severity. CVSS v3 base score is 4.8 out of 10.