Is CVE-2018-5174 in the CISA KEV catalog?

No. CVE-2018-5174 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2018-5174?

CVE-2018-5174 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2018-5174?

CVE-2018-5174 has an EPSS score of 1.87% (77th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2018-5174?

Upgrade DeveloperEdition to 52.8.0 or later. Fixes are available for 3 affected products.

CVE & CISA-KEV Catalog

CVE-2018-5174

HIGHEPSS 77th pctl

7.5

CVSS v3

NVD

Description

In the Windows 10 April 2018 Update, Windows Defender SmartScreen honors the "SEE_MASK_FLAG_NO_UI" flag associated with downloaded files and will not show any UI. Files that are unknown and potentially dangerous will be allowed to run because SmartScreen will not prompt the user for a decision, and if the user is offline all files will be allowed to be opened because Windows won't prompt the user to ask what to do. Firefox incorrectly sets this flag when downloading files, leading to less secure behavior from SmartScreen. Note: this issue only affects Windows 10 users running the April 2018 update or later. It does not affect other Windows users or other operating systems. This vulnerability affects Thunderbird < 52.8, Thunderbird ESR < 52.8, Firefox < 60, and Firefox ESR < 52.8.

How to fix

Remediation Available

DeveloperEditionWindows application

Affected:52.8.0Fixed in:52.8.0Mozilla

Affected:60.0Fixed in:60.0Mozilla

Mozilla Firefox (en-US)Windows application

Affected:60.0Fixed in:60.0Mozilla

Affected:52.8.0Fixed in:52.8.0Mozilla

Mozilla Thunderbird (en-US)Windows application

Affected:52.8.0Fixed in:52.8.0Mozilla

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityHigh

AvailabilityNone

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Exploit Intelligence

1.87%probability of exploitation in 30 days

77thpercentile

Elevated risk: more likely to be exploited than 77% of all known CVEs.

References

Vendor Advisory3

Third-Party Advisory3

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-11-25.