CVE-2017-11786
Skype for Business in Microsoft Lync 2013 SP1 and Skype for Business 2016 allows an attacker to steal an authentication hash that can be reused elsewhere, due to how Skype for Business handles authentication requests, aka "Skype for Business Elevation…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (9.39%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Skype for Business in Microsoft Lync 2013 SP1 and Skype for Business 2016 allows an attacker to steal an authentication hash that can be reused elsewhere, due to how Skype for Business handles authentication requests, aka "Skype for Business Elevation of Privilege Vulnerability."
- CVSS 3.0
- 8.8 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- EPSS
- 9.39% probability · 95th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-294
- Affected
- microsoft/lync · microsoft/skype for business
- Source
- secure@microsoft.com
EPSS moved from 8.1% on 21 September 2026 to 9.4% on 27 October 2026. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”.
References
- http://www.securityfocus.com/bid/101156Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1039530Third Party Advisory, VDB Entry
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-11786Patch, Vendor Advisory
- http://www.securityfocus.com/bid/101156Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1039530Third Party Advisory, VDB Entry
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-11786Patch, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.