CVE-2026-66307
Skype for Business and Lync Denial of Service vulnerability
MSRC advisory September 8, 2026
Alert details
- Source feed
- Microsoft MSRC
- CVE ID
- CVE-2026-66307
- CWE
- CWE-191
- Affected products
- Skype for Business and Lync Denial of Service · Microsoft Skype for Business and Lync Denial of Service · Microsoft
What happened
<p>Integer underflow (wrap or wraparound) in Skype for Business allows an unauthorized attacker to deny service over a network.</p>
What it means for your business
Skype for Business and Lync Denial of Service vulnerability (CVE-2026-66307) was added to Microsoft’s security update guidance. <p>Integer underflow (wrap or wraparound) in Skype for Business allows an unauthorized attacker to deny service over a network.</p> If you need help checking exposure, call (864) 335-9223.
CVSS score
7.5 (High)
EPSS probability
0.63%
Sources
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