CVE-2026-69646: Microsoft Skype For Business Server

High severity, CVSS 8.3. EPSS: 0.3% chance of exploitation in the next 30 days.

Improper verification of cryptographic signature in Skype for Business allows an unauthorized attacker to perform spoofing over an adjacent network.

Affected products

• Microsoft Skype For Business Server: version 2015 only; version 2019 only
• Microsoft Skype For Business Server Subscription Edition: version 7.0.2046.849 only

Published 2026-09-08. Last modified 2026-09-16.