A security feature bypass vulnerability exists when Skype for Business or Lync do not properly parse UNC path links shared via messages, ak…

published 2018-07-11 8y ago modified 2026-06-17 4mo ago also EUVD-2018-19905

cvss: 7.8; version 3.0, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 6.0%; EPSS 6.0% chance of exploitation in 30 days, percentile 93%
public exploits: 0; none known

A security feature bypass vulnerability exists when Skype for Business or Lync do not properly parse UNC path links shared via messages, aka "Skype for Business and Lync Security Feature Bypass Vulnerability." This affects Skype, Microsoft Lync.

Patch / fix

links 1

portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8238 advisory

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Exploit prediction

5.99% chance of exploitation in the next 30 days, higher than 93% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
NVD	3.0	7.8	CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD	2.0	9.3	AV:N/AC:M/Au:N/C:C/I:C/A:C

Affected products

Microsoft Skype
Microsoft Microsoft Lync

References

portal.msrc.microsoft.com /en-US/security-guidance/advisory/CVE-2018-8238
patch, vendor-advisory
securityfocus.com /bid/104619
vdb-entry, third-party-advisory

Sources

CVE List CVE-2018-8238
NVD CVE-2018-8238

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