CVE-2026-66307
High
Description
Integer underflow (wrap or wraparound) in Skype for Business allows an unauthorized attacker to deny service over a network.
SeverityHigh
CVSS7.5
Exploit probability—
Product
Microsoft Skype For Business Server
PublishedSep 8, 2026
First seenSep 8, 2026
Weakness typeCWE-191CWE-191
How to fix
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| microsoft skype_for_business_server | 2015, 2019 | — |
| microsoft skype_for_business_server_subscription_edition | 7.0.2046.849 | — |
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