CVE-2018-8238

CVE-2018-8238 is a high-severity vulnerability in Microsoft Lync with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

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.

Frequently asked questions

What is CVE-2018-8238?
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.
How severe is CVE-2018-8238?
CVE-2018-8238 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-8238 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (92nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-8238?
CVE-2018-8238 primarily affects Microsoft Lync. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-8238?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2018-8238 published?
CVE-2018-8238 was published on 2018-07-11 and last updated on 2026-06-17.

References

Affected products (2)

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