How severe is CVE-2010-2566?

CVE-2010-2566 has a CVSS 2.0 base score of 9.3, rated critical severity.

Is CVE-2010-2566 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 15% (96th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2010-2566?

CVE-2010-2566 primarily affects Microsoft Windows 2003 Server. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2010-2566?

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-2010-2566 published?

CVE-2010-2566 was published on 2010-08-11 and last updated on 2026-06-16.

CVE-2010-2566

CVE-2010-2566 is a critical-severity vulnerability in Microsoft Windows 2003 Server with a CVSS 2.0 base score of 9.3. Its EPSS exploit-prediction score of 15% places it in the 96th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-20.

Key facts

Severity: Critical (CVSS 2.0 base score 9.3)
EPSS exploit prediction: 15% (96th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Microsoft Windows 2003 Server
Published: 2010-08-11
Last modified: 2026-06-16

Description

The Secure Channel (aka SChannel) security package in Microsoft Windows XP SP2 and SP3, and Windows Server 2003 SP2, does not properly validate certificate request messages from TLS and SSL servers, which allows remote servers to execute arbitrary code via a crafted SSL response, aka "SChannel Malformed Certificate Request Remote Code Execution Vulnerability."

Frequently asked questions

What is CVE-2010-2566?: The Secure Channel (aka SChannel) security package in Microsoft Windows XP SP2 and SP3, and Windows Server 2003 SP2, does not properly validate certificate request messages from TLS and SSL servers, which allows remote servers to execute arbitrary code via a crafted SSL response, aka "SChannel Malformed Certificate Request Remote Code Execution Vulnerability."
How severe is CVE-2010-2566?: CVE-2010-2566 has a CVSS 2.0 base score of 9.3, rated critical severity.
Is CVE-2010-2566 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 15% (96th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2010-2566?: CVE-2010-2566 primarily affects Microsoft Windows 2003 Server. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2010-2566?: 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-2010-2566 published?: CVE-2010-2566 was published on 2010-08-11 and last updated on 2026-06-16.

References

Affected products (5)

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_server_2003:*:sp2:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_xp:*:sp3:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_xp:-:sp2:x64:*:*:*:*:*

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