How severe is CVE-2011-1889?

CVE-2011-1889 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2011-1889 being actively exploited?

Yes. CVE-2011-1889 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2022-03-03, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2011-1889?

CVE-2011-1889 affects Microsoft Forefront Threat Management Gateway. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2011-1889?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

Does CVE-2011-1889 have an EU (EUVD) identifier?

Yes. CVE-2011-1889 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2011-1887. It is also flagged as exploited in the EUVD (since 2022-03-03).

When was CVE-2011-1889 published?

CVE-2011-1889 was published on 2011-06-16 and last updated on 2026-06-16.

CVE-2011-1889

CVE-2011-1889 is a critical-severity vulnerability in Microsoft Forefront Threat Management Gateway with a CVSS 3.x base score of 9.8. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2022-03-03). The underlying weakness is classified as CWE-119.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 10.0
EPSS exploit prediction: 48% (99th percentile)
Actively exploited: Yes — listed in CISA KEV (added 2022-03-03)
EU (EUVD) id: EUVD-2011-1887
EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2022-03-03)
Weakness: CWE-119
Affected product: Microsoft Forefront Threat Management Gateway
Published: 2011-06-16
Last modified: 2026-06-16

Description

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."

Frequently asked questions

What is CVE-2011-1889?: 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."
How severe is CVE-2011-1889?: CVE-2011-1889 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2011-1889 being actively exploited?: Yes. CVE-2011-1889 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2022-03-03, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2011-1889?: CVE-2011-1889 affects Microsoft Forefront Threat Management Gateway. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2011-1889?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2011-1889 have an EU (EUVD) identifier?: Yes. CVE-2011-1889 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2011-1887. It is also flagged as exploited in the EUVD (since 2022-03-03).
When was CVE-2011-1889 published?: CVE-2011-1889 was published on 2011-06-16 and last updated on 2026-06-16.

References

Affected products (1)

cpe:2.3:a:microsoft:forefront_threat_management_gateway:2010:*:*:*:*:*:*:*

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