Spoofing Vulnerability in Skype for Business by Microsoft
CVE-2026-69646

8.3HIGH

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-2026-69646?

The vulnerability in Skype for Business arises from inadequate verification of cryptographic signatures, which allows an unauthorized attacker to execute spoofing attacks over adjacent networks. This could lead to unauthorized access and potentially compromise the integrity of communication within the organization. Organizations using Skype for Business should evaluate their security measures and consider applying available patches to mitigate this risk.

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:
8.3
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Adjacent Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.