Sep 2026: Skype for Business and Lync Denial of Service Vulnerability
CVE-2026-66307 Published on September 8, 2026
Skype for Business and Lync Denial of Service Vulnerability
Integer underflow (wrap or wraparound) in Skype for Business allows an unauthorized attacker to deny service over a network.
Weakness Type
What is an Integer underflow Vulnerability?
The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result. This can happen in signed and unsigned cases.
CVE-2026-66307 has been classified to as an Integer underflow vulnerability or weakness.
Products Associated with CVE-2026-66307
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Affected Versions
Microsoft Skype for Business Server 2015 CU13:- Version 9319.0 and below 6.0.9319.885 is affected.
- Version 2046.0 and below 7.0.2046.569 is affected.
- Version 2046.0 and below 7.0.2046.879 is affected.