How severe is CVE-2025-21377?

CVE-2025-21377 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2025-21377 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 22% (97th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-21377?

CVE-2025-21377 primarily affects Microsoft Windows 10 1507. In total, 21 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2025-21377?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2025-21377 have an EU (EUVD) identifier?

Yes. CVE-2025-21377 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-2440.

When was CVE-2025-21377 published?

CVE-2025-21377 was published on 2025-02-11 and last updated on 2026-06-17.

CVE-2025-21377

CVE-2025-21377 is a medium-severity vulnerability in Microsoft Windows 10 1507 with a CVSS 3.x base score of 6.5. Its EPSS exploit-prediction score of 22% places it in the 97th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-73.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
EPSS exploit prediction: 22% (97th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-2440
Weakness: CWE-73
Affected product: Microsoft Windows 10 1507
Published: 2025-02-11
Last modified: 2026-06-17

Description

NTLM Hash Disclosure Spoofing Vulnerability

Frequently asked questions

What is CVE-2025-21377?: NTLM Hash Disclosure Spoofing Vulnerability
How severe is CVE-2025-21377?: CVE-2025-21377 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2025-21377 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 22% (97th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-21377?: CVE-2025-21377 primarily affects Microsoft Windows 10 1507. In total, 21 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-21377?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-21377 have an EU (EUVD) identifier?: Yes. CVE-2025-21377 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-2440.
When was CVE-2025-21377 published?: CVE-2025-21377 was published on 2025-02-11 and last updated on 2026-06-17.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21377

Affected products (21)

cpe:2.3:o:microsoft:windows_10_1507:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_1507:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_11_22h2:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:*

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