How severe is CVE-2009-1127?

CVE-2009-1127 has a CVSS 2.0 base score of 7.2, rated high severity.

Is CVE-2009-1127 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-1127?

CVE-2009-1127 primarily affects Microsoft Windows 2000. In total, 17 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-1127?

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-2009-1127 published?

CVE-2009-1127 was published on 2009-11-11 and last updated on 2026-06-16.

CVE-2009-1127

CVE-2009-1127 is a high-severity vulnerability in Microsoft Windows 2000 with a CVSS 2.0 base score of 7.2. 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-20.

Key facts

Severity: High (CVSS 2.0 base score 7.2)
EPSS exploit prediction: 2% (72nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Microsoft Windows 2000
Published: 2009-11-11
Last modified: 2026-06-16

Description

win32k.sys in the kernel in Microsoft Windows 2000 SP4, XP SP2 and SP3, Server 2003 SP2, Vista Gold, SP1, and SP2, and Server 2008 Gold and SP2 does not correctly validate an argument to an unspecified system call, which allows local users to gain privileges via a crafted application that triggers a NULL pointer dereference, aka "Win32k NULL Pointer Dereferencing Vulnerability."

Frequently asked questions

What is CVE-2009-1127?: win32k.sys in the kernel in Microsoft Windows 2000 SP4, XP SP2 and SP3, Server 2003 SP2, Vista Gold, SP1, and SP2, and Server 2008 Gold and SP2 does not correctly validate an argument to an unspecified system call, which allows local users to gain privileges via a crafted application that triggers a NULL pointer dereference, aka "Win32k NULL Pointer Dereferencing Vulnerability."
How severe is CVE-2009-1127?: CVE-2009-1127 has a CVSS 2.0 base score of 7.2, rated high severity.
Is CVE-2009-1127 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-1127?: CVE-2009-1127 primarily affects Microsoft Windows 2000. In total, 17 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-1127?: 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-2009-1127 published?: CVE-2009-1127 was published on 2009-11-11 and last updated on 2026-06-16.

References

Affected products (17)

cpe:2.3:o:microsoft:windows_2000:*:sp4:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_2003_server:*:sp2:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_2003_server:*:sp2:itanium:*:*:*:*:*
cpe:2.3:o:microsoft:windows_2003_server:*:sp2:x64:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:*:*:x32:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:*:*:x64:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:*:sp2:x32:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:*:sp2:x64:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:-:gold:itanium:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:-:sp2:itanium:*:*:*:*:*
cpe:2.3:o:microsoft:windows_vista:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_vista:*:*:x64:*:*:*:*:*
cpe:2.3:o:microsoft:windows_vista:*:sp1:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_vista:*:sp2:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_xp:*:sp2:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_xp:*:sp3:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_xp:-:sp2:x64:*:*:*:*:*

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