NTLM Is Going Away: What Microsoft's Phaseout Means For MSPs And IT Teams
Barracuda Networks, Monday, March 2nd, 2026
Why legacy authentication is a growing security risk-and how to prepare for a Kerberos‑first Windows environment
Takeaways
- NTLM is a known security risk that enables techniques commonly used in ransomware and other attacks.
- Deprecation is already underway, and future Windows releases will disable NTLM by default unless explicitly re‑enabled.
- Identifying hidden NTLM dependencies and validating Kerberos compatibility are critical for a successful migration.
Microsoft is slowly phasing out its long-standing authentication protocol, NT LAN Manager, or NTLM. This is one of those legacy technologies that has worked 'well-enough' for decades, since the first version was introduced in 1993 with Windows NT 3.1. Microsoft rolled out NTLMv2 six years later in Windows NT 4.0 Service Pack 4.