How severe is CVE-2019-1365?

CVE-2019-1365 has a CVSS 3.x base score of 9.9, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2019-1365 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-1365?

CVE-2019-1365 primarily affects Microsoft Windows 10. In total, 16 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2019-1365?

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-2019-1365 published?

CVE-2019-1365 was published on 2019-10-10 and last updated on 2026-06-17.

CVE-2019-1365

CVE-2019-1365 is a critical-severity vulnerability in Microsoft Windows 10 with a CVSS 3.x base score of 9.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Critical (CVSS 3.x base score 9.9)
CVSS v2: 9.0
EPSS exploit prediction: 4% (89th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Microsoft Windows 10
Published: 2019-10-10
Last modified: 2026-06-17

Description

An elevation of privilege vulnerability exists when Microsoft IIS Server fails to check the length of a buffer prior to copying memory to it.An attacker who successfully exploited this vulnerability can allow an unprivileged function ran by the user to execute code in the context of NT AUTHORITY\system escaping the Sandbox.The security update addresses the vulnerability by correcting how Microsoft IIS Server sanitizes web requests., aka 'Microsoft IIS Server Elevation of Privilege Vulnerability'.

Frequently asked questions

What is CVE-2019-1365?: An elevation of privilege vulnerability exists when Microsoft IIS Server fails to check the length of a buffer prior to copying memory to it.An attacker who successfully exploited this vulnerability can allow an unprivileged function ran by the user to execute code in the context of NT AUTHORITY\system escaping the Sandbox.The security update addresses the vulnerability by correcting how Microsoft IIS Server sanitizes web requests., aka 'Microsoft IIS Server Elevation of Privilege Vulnerability'.
How severe is CVE-2019-1365?: CVE-2019-1365 has a CVSS 3.x base score of 9.9, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2019-1365 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-1365?: CVE-2019-1365 primarily affects Microsoft Windows 10. In total, 16 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2019-1365?: 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-2019-1365 published?: CVE-2019-1365 was published on 2019-10-10 and last updated on 2026-06-17.

References

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1365

Affected products (16)

cpe:2.3:o:microsoft:windows_10:1607:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:1803:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:1809:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:1903:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_7:-:sp1:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_rt_8.1:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:itanium:*
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_2016:1803:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:1903:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2019:-:*:*:*:*:*:*:*

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