Microsoft Forefront TMG Remote Code Execution Vulnerability

What it is

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.

Who's affected

Affects anyone running Microsoft Forefront Threat Management Gateway (TMG). Microsoft products in a small practice typically sit close to credentials, email, or document workflows — treat the patch as in-scope.

What to do

Apply updates per vendor instructions.

If you don't have someone in-house to verify the patch deployed across every endpoint — or you're not sure whether you're affected — that's exactly the kind of triage we do. Book a free 20-minute triage call.

CISA due date

CISA's listed due date: March 24, 2022.

Federal civilian agencies work under CISA's Binding Operational Directive 26-04, which replaced BOD 22-01 on June 10, 2026. It sets the deadline for each affected system by:

• How exposed that system is to the internet
• Whether the attack can be automated
• How much control it gives an attacker

Its table gives catalogued vulnerabilities 3 or 14 days.

None of this binds a private business, but treat the date as a strong recommendation, especially if you handle regulated data (HIPAA, GLBA, ABA model rules).

EPSS

EPSS score: 49.0% — higher than 99% of all scored CVEs.

EPSS estimates the probability of exploitation activity in the next 30 days. Every entry on this site is already confirmed exploited, so read it as relative urgency among the things you still have open, not as permission to wait.

Score dated 2026-09-26, from the FIRST.org Exploit Prediction Scoring System.

Browse more

• All Microsoft KEV entries
• All SMB-relevant KEV entries

Source

This entry comes from CISA's Known Exploited Vulnerabilities catalog, public US-Government data we pull daily. The plain-language framing and the what-to-do guidance above are ours. View the original entry on cisa.gov.