Null Pointer Dereference in Skype for Business Causes Service Disruption by Microsoft
CVE-2026-66303

6.5MEDIUM

Key Information:

Vendor

Microsoft
Status
Skype For Business Server 2015 Cu13
Skype For Business Server 2019 Cu8
Skype For Business Server Subscription Edition Cu1
Vendor
CVE Published:
8 September 2026

What is CVE-2026-66303?

A null pointer dereference vulnerability exists in Skype for Business that can be exploited by an authorized attacker, potentially resulting in service disruption over the network. This issue allows attackers to execute a denial of service, impacting the availability of the application. Users of Skype for Business should stay informed about this vulnerability and apply necessary updates provided by Microsoft to mitigate the risks.

Affected Version(s)

Skype for Business Server 2015 CU13 x64-based Systems 9319.0 < 6.0.9319.885

Skype for Business Server 2019 CU8 x64-based Systems 2046.0 < 7.0.2046.569

Skype for Business Server Subscription Edition CU1 x64-based Systems 2046.0 < 7.0.2046.879

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE...
vendor-advisorypatch

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.