CVE-2011-1889: in the CISA KEV catalogue
Microsoft Forefront TMG Remote Code Execution Vulnerability. CISA added CVE-2011-1889 to the Known Exploited Vulnerabilities catalogue on 2022-03-03 with a default due date of 2022-03-24. Known ransomware campaign use: Unknown. Forensic triage flag: No.
A remote code execution vulnerability exists in the Forefront Threat Management Gateway (TMG) Firewall Client Winsock provider that could allow code execution in the security context of the client application. (CISA description)
- Vendor / product
- Microsoft Forefront Threat Management Gateway (TMG)
- CWE
- CWE-119
- CISA required action
- Apply updates per vendor instructions.
- EPSS
- 49%, percentile 98 (scored 2026-11-03)
EPSS puts about 49 in 100 odds (49%) on exploitation activity being observed in the next 30 days. Its score is higher than or equal to that of 98% of scored CVEs. This is a model estimate about exploitation anywhere, not about your environment.
Vendor and reference links (from CISA)
Your own deadline under CISA BOD 26-04 depends on exposure, automatability and technical impact: work it out with the BOD 26-04 calculator.
Frequently asked questions
Is CVE-2011-1889 in the CISA KEV catalogue?
Yes. CISA added CVE-2011-1889 (Microsoft Forefront TMG Remote Code Execution Vulnerability) to the Known Exploited Vulnerabilities catalogue on 2022-03-03. CISA's default due date for it is 2022-03-24.
Is CVE-2011-1889 used in ransomware attacks?
CISA marks known ransomware campaign use as Unknown for CVE-2011-1889. That means CISA lacks confirmation, not that ransomware groups do not use it.
What should I do about CVE-2011-1889?
CISA's required action: Apply updates per vendor instructions.
Sources
- CISA, Known Exploited Vulnerabilities Catalog (accessed 2026-11-03)
- FIRST, Exploit Prediction Scoring System (EPSS) (EPSS by FIRST; scores generated by Empirical Security)
- NVD record for CVE-2011-1889