What is CVE-2018-8326?

CVE-2018-8326 is a medium-severity vulnerability in Microsoft Web Customizations, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2018-07-11.

How severe is CVE-2018-8326?

Medium severity. CVSS v3 base score is 5.4 out of 10.

XSS in Microsoft Web Customizations

CVE-2018-8326

A cross-site-scripting (XSS) vulnerability exists when an open source customization for Microsoft Active Directory Federation Services (AD FS) does not properly sanitize a specially crafted web request to an affected AD FS server, aka "Open Source Customization for Active Directory Federation Services XSS Vulnerability." This affects Web Customizations.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2018-07-11 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.026 (84.6th percentile), scored 2026-10-03.

Low probability of exploitation in the next 30 days, but still tracked. 85th percentile — 84.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.024 · newest: 0.026 · change: +0.002

Affected products

Microsoft Web Customizations — versions Active Directory Federation Services
Microsoft Web Customizations

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8326 (Patch, Vendor Advisory)
www.securitytracker.com/id/1041266 (VDB Entry, Third Party Advisory, vdb-entry)
www.securityfocus.com/bid/104656 (VDB Entry, Third Party Advisory, vdb-entry)

Frequently asked questions

What is CVE-2018-8326?: CVE-2018-8326 is a medium-severity vulnerability in Microsoft Web Customizations, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2018-07-11.
How severe is CVE-2018-8326?: Medium severity. CVSS v3 base score is 5.4 out of 10.