How severe is CVE-1999-0366?

CVE-1999-0366 has a CVSS 2.0 base score of 7.5, rated high severity.

Is CVE-1999-0366 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-1999-0366?

CVE-1999-0366 affects Microsoft Windows Nt. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-1999-0366?

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-1999-0366 published?

CVE-1999-0366 was published on 1999-02-08 and last updated on 2026-06-16.

CVE-1999-0366

CVE-1999-0366 is a high-severity vulnerability in Microsoft Windows Nt with a CVSS 2.0 base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-287.

Key facts

Severity: High (CVSS 2.0 base score 7.5)
EPSS exploit prediction: 4% (88th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Microsoft Windows Nt
Published: 1999-02-08
Last modified: 2026-06-16

Description

In some cases, Service Pack 4 for Windows NT 4.0 can allow access to network shares using a blank password, through a problem with a null NT hash value.

Frequently asked questions

What is CVE-1999-0366?: In some cases, Service Pack 4 for Windows NT 4.0 can allow access to network shares using a blank password, through a problem with a null NT hash value.
How severe is CVE-1999-0366?: CVE-1999-0366 has a CVSS 2.0 base score of 7.5, rated high severity.
Is CVE-1999-0366 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-1999-0366?: CVE-1999-0366 affects Microsoft Windows Nt. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-1999-0366?: 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-1999-0366 published?: CVE-1999-0366 was published on 1999-02-08 and last updated on 2026-06-16.

References

Affected products (1)

cpe:2.3:o:microsoft:windows_nt:4.0:sp4:*:*:*:*:*:*

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