How severe is CVE-2026-20818?

CVE-2026-20818 has a CVSS 3.x base score of 6.2, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-20818 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-20818?

CVE-2026-20818 primarily affects Microsoft Windows Server 2016. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-20818?

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

Does CVE-2026-20818 have an EU (EUVD) identifier?

Yes. CVE-2026-20818 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-2190.

When was CVE-2026-20818 published?

CVE-2026-20818 was published on 2026-01-13 and last updated on 2026-06-17.

CVE-2026-20818

CVE-2026-20818 is a medium-severity vulnerability in Microsoft Windows Server 2016 with a CVSS 3.x base score of 6.2. 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-532.

Key facts

Severity: Medium (CVSS 3.x base score 6.2)
EPSS exploit prediction: 1% (48th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-2190
Weakness: CWE-532
Affected product: Microsoft Windows Server 2016
Published: 2026-01-13
Last modified: 2026-06-17

Description

Insertion of sensitive information into log file in Windows Kernel allows an unauthorized attacker to disclose information locally.

Frequently asked questions

What is CVE-2026-20818?: Insertion of sensitive information into log file in Windows Kernel allows an unauthorized attacker to disclose information locally.
How severe is CVE-2026-20818?: CVE-2026-20818 has a CVSS 3.x base score of 6.2, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-20818 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-20818?: CVE-2026-20818 primarily affects Microsoft Windows Server 2016. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-20818?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-20818 have an EU (EUVD) identifier?: Yes. CVE-2026-20818 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-2190.
When was CVE-2026-20818 published?: CVE-2026-20818 was published on 2026-01-13 and last updated on 2026-06-17.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20818

Affected products (5)

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:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*

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