CVE-2011-3402: Microsoft Windows Remote Code Execution Vulnerability

Is it exploited?

Yes. CISA added it to the Known Exploited Vulnerabilities catalog on 6 Oct 2025, 5,085 days after the CVE record was published.

How likely is exploitation in the next 30 days?

78.1%

EPSS score, percentile 99.6 of all scored records

How severe?

8.8 High

CVSS v3.1 base score, from CISA's enrichment of the record

What should I do?

CISA deadline 27 Oct 2025. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Advisories and patches (3)

Which versions are affected?

Not stated. The CVE record gives vendor and product as “n/a” and the version as “unspecified”.

Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

What to do

CISA due date for this action: 27 October 2025.

Advisories and patches

• MS11-087 (Vendor advisory)
• MS12-034 (Vendor advisory)
• MS12-039 (Vendor advisory)

Linked from CISA's catalog entry

• https://docs.microsoft.com/en-us/security-updates/securitybulletins/2011/ms11-087
• https://nvd.nist.gov/vuln/detail/CVE-2011-3402

Affected products and versions

The CVE record does not name affected products or versions: vendor and product are “n/a” and the version is “unspecified”.

Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

About this vulnerability

Microsoft Windows Kernel contains an unspecified vulnerability in the TrueType font parsing engine in win32k.sys in the kernel-mode drivers that allows remote attackers to execute arbitrary code via crafted font data in a Word document or web page.

Summary: CISA's KEV catalog, as of 28 Oct 2026.

• CISA added CVE-2011-3402 to its Known Exploited Vulnerabilities (KEV) catalog on 6 Oct 2025.
• CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
• The due date CISA sets for the required action is 27 Oct 2025.
• The CVE record was published on 4 Nov 2011, 5,085 days before it was added to KEV.
• The CVE record carries a CVSS v3.1 base score of 8.8 (High), taken from CISA's enrichment of the record.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 78.1% (percentile 99.6), as of 28 Oct 2026.
• CISA's SSVC assessment in the CVE record: exploitation active, automatable no, technical impact total.

Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026. About the data.

Description

Unspecified vulnerability in the TrueType font parsing engine in win32k.sys in the kernel-mode drivers in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2, R2, and R2 SP1, and Windows 7 Gold and SP1 allows remote attackers to execute arbitrary code via crafted font data in a Word document or web page, as exploited in the wild in November 2011 by Duqu, aka "TrueType Font Parsing Vulnerability."

Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

Timeline

References

• 49121 (Third-party advisory)
• TA12-164A (Third-party advisory)
• 49122 (Third-party advisory)
• TA11-347A (Third-party advisory)
• TA12-129A (Third-party advisory)
• oval:org.mitre.oval:def:15645 (Vulnerability database)
• 1027039 (Vulnerability database)
• oval:org.mitre.oval:def:13998 (Vulnerability database)
• oval:org.mitre.oval:def:15290 (Vulnerability database)

8 more in the CVE record.

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