How severe is CVE-2018-8626?

CVE-2018-8626 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2018-8626 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 21% (97th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-8626?

CVE-2018-8626 primarily affects Microsoft Windows 10. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-8626?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2018-8626 published?

CVE-2018-8626 was published on 2018-12-12 and last updated on 2026-06-17.

CVE-2018-8626

CVE-2018-8626 is a critical-severity vulnerability in Microsoft Windows 10 with a CVSS 3.x base score of 9.8. Its EPSS exploit-prediction score of 21% places it in the 97th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-787.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 10.0
EPSS exploit prediction: 21% (97th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Microsoft Windows 10
Published: 2018-12-12
Last modified: 2026-06-17

Description

A remote code execution vulnerability exists in Windows Domain Name System (DNS) servers when they fail to properly handle requests, aka "Windows DNS Server Heap Overflow Vulnerability." This affects Windows Server 2012 R2, Windows Server 2019, Windows Server 2016, Windows 10, Windows 10 Servers.

Frequently asked questions

What is CVE-2018-8626?: A remote code execution vulnerability exists in Windows Domain Name System (DNS) servers when they fail to properly handle requests, aka "Windows DNS Server Heap Overflow Vulnerability." This affects Windows Server 2012 R2, Windows Server 2019, Windows Server 2016, Windows 10, Windows 10 Servers.
How severe is CVE-2018-8626?: CVE-2018-8626 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-8626 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 21% (97th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-8626?: CVE-2018-8626 primarily affects Microsoft Windows 10. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-8626?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2018-8626 published?: CVE-2018-8626 was published on 2018-12-12 and last updated on 2026-06-17.

References

Affected products (9)

cpe:2.3:o:microsoft:windows_10:1607:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:1709:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:1803:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:1809:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:1709:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:1803:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2019:-:*:*:*:*:*:*:*

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