CVE-2026-83746: Skype for Business Elevation of Privilege Vulnerability

Severity: high (CVSS 8.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-13 · updated 2026-10-31
Weakness: CWE-36

Description

Absolute path traversal in Skype for Business and Microsoft Lync allows an authorized attacker to elevate privileges over a network.

Affected products

Microsoft Skype for Business Server 2015 CU13: from 9319.0 before 6.0.9319.886 — fixed in 6.0.9319.886
Microsoft Skype for Business Server 2019 CU8: from 2046.0 before 7.0.2046.583 — fixed in 7.0.2046.583
Microsoft Skype for Business Server Subscription Edition CU1: from 2046.0 before 7.0.2046.889 — fixed in 7.0.2046.889

How to fix

Upgrade to a fixed version: Microsoft Skype for Business Server 2015 CU13 6.0.9319.886; Microsoft Skype for Business Server 2019 CU8 7.0.2046.583; Microsoft Skype for Business Server Subscription Edition CU1 7.0.2046.889. Check the vendor advisory for mitigations.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83746

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