What is CVE-2026-63523?

CVE-2026-63523 is a medium-severity vulnerability in Microsoft Skype For Business Server 2015 Cu13, classified under Cross-site Scripting. CVSS score: 6.5/10. Published 2026-09-08.

How severe is CVE-2026-63523?

Medium severity. CVSS v3 base score is 6.5 out of 10.

XSS in Microsoft Skype For Business Server 2015 Cu13

CVE-2026-63523

Improper neutralization of input during web page generation ('cross-site scripting') in Skype for Business allows an unauthorized attacker to perform spoofing over a network.

Vulnerability class: XSS (Cross-Site Scripting)

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.

Affected products

Microsoft Skype For Business Server 2015 Cu13

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

secure@microsoft.com (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-63523?: CVE-2026-63523 is a medium-severity vulnerability in Microsoft Skype For Business Server 2015 Cu13, classified under Cross-site Scripting. CVSS score: 6.5/10. Published 2026-09-08.
How severe is CVE-2026-63523?: Medium severity. CVSS v3 base score is 6.5 out of 10.