Is CVE-2011-1889 being actively exploited?

Yes. CVE-2011-1889 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added on March 3, 2022.

What is the CVSS score for CVE-2011-1889?

CVE-2011-1889 has a CVSS 3.1 base score of 9.8 (CRITICAL).

CVE-2011-1889

CRITICAL · CVSS 9.8CISA KEV: actively exploitedEPSS 49.0%EU EUVD: exploited

The NSPLookupServiceNext function in the client in Microsoft Forefront Threat Management Gateway (TMG) 2010 allows remote attackers to execute arbitrary code via vectors involving unspecified requests, aka "TMG Firewall Client Memory Corruption Vulnerability."

Key facts

CVSS score: 9.8 (v3.1)
Severity: CRITICAL
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-119
EPSS score: 49.0% (99th percentile)
In CISA KEV: Yes, added March 3, 2022
In EU EUVD: Yes (EUVD-2011-1887)
Published: June 16, 2011
NVD last modified: June 16, 2026
Status: Analyzed

CISA Known Exploited Vulnerability

Microsoft Forefront TMG Remote Code Execution Vulnerability

Added to the KEV catalog on March 3, 2022; federal remediation due March 24, 2022.

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2011-1887 in the EU Vulnerability Database. ENISA flags it as known exploited. Last updated in EUVD on October 22, 2025.

View on the EU Vulnerability Database

Affected products

microsoft / forefront threat management gateway

References

http://secunia.com/advisories/44857(Broken Link)
http://www.securityfocus.com/bid/48181(Broken Link, Third Party Advisory, VDB Entry)
http://www.securitytracker.com/id?1025637(Broken Link, Third Party Advisory, VDB Entry)
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2011/ms11-040(Patch, Vendor Advisory)
https://exchange.xforce.ibmcloud.com/vulnerabilities/67736(Third Party Advisory, VDB Entry)
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A12642(Broken Link)
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2011-1889(US Government Resource)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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