How severe is CVE-2023-21539?

CVE-2023-21539 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-21539 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (63rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-21539?

CVE-2023-21539 primarily affects Microsoft Windows 10 20h2. In total, 14 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-21539?

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-2023-21539 published?

CVE-2023-21539 was published on 2023-01-10 and last updated on 2026-06-17.

CVE-2023-21539

CVE-2023-21539 is a high-severity vulnerability in Microsoft Windows 10 20h2 with a CVSS 3.x 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-125.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (63rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Microsoft Windows 10 20h2
Published: 2023-01-10
Last modified: 2026-06-17

Description

Windows Authentication Remote Code Execution Vulnerability

Frequently asked questions

What is CVE-2023-21539?: Windows Authentication Remote Code Execution Vulnerability
How severe is CVE-2023-21539?: CVE-2023-21539 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-21539 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (63rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-21539?: CVE-2023-21539 primarily affects Microsoft Windows 10 20h2. In total, 14 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-21539?: 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-2023-21539 published?: CVE-2023-21539 was published on 2023-01-10 and last updated on 2026-06-17.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21539

Affected products (14)

cpe:2.3:o:microsoft:windows_10_20h2:-:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_10_20h2:-:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_20h2:-:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_10_21h2:-:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_10_21h2:-:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_21h2:-:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_10_22h2:-:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_10_22h2:-:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_22h2:-:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_11_21h2:-:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_21h2:-:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_22h2:-:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_22h2:-:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2022:-:*:*:*:*:*:*:*

More vulnerabilities in Microsoft Windows 10 20h2

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