Description
Improper authorization in Windows Kerberos allows an authorized attacker to elevate privileges over an adjacent network.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Microsoft | Windows Server 2012 | 6.2.9200.0 – < 6.2.9200.26026 | 6.2.9200.26026 |
| Microsoft | Windows Server 2012 (Server Core installation) | 6.2.9200.0 – < 6.2.9200.26026 | 6.2.9200.26026 |
| Microsoft | Windows Server 2012 R2 | 6.3.9600.0 – < 6.3.9600.23132 | 6.3.9600.23132 |
| Microsoft | Windows Server 2012 R2 (Server Core installation) | 6.3.9600.0 – < 6.3.9600.23132 | 6.3.9600.23132 |
| Microsoft | Windows Server 2016 | 10.0.14393.0 – < 10.0.14393.9060 | 10.0.14393.9060 |
| Microsoft | Windows Server 2016 (Server Core installation) | 10.0.14393.0 – < 10.0.14393.9060 | 10.0.14393.9060 |
| Microsoft | Windows Server 2019 | 10.0.17763.0 – < 10.0.17763.8644 | 10.0.17763.8644 |
| Microsoft | Windows Server 2019 (Server Core installation) | 10.0.17763.0 – < 10.0.17763.8644 | 10.0.17763.8644 |
| Microsoft | Windows Server 2022 | 10.0.20348.0 – < 10.0.20348.5020 | 10.0.20348.5020 |
| Microsoft | Windows Server 2022, 23H2 Edition (Server Core installation) | 10.0.25398.0 – < 10.0.25398.2274 | 10.0.25398.2274 |
| Microsoft | Windows Server 2025 | 10.0.26100.0 – < 10.0.26100.32690 | 10.0.26100.32690 |
| Microsoft | Windows Server 2025 (Server Core installation) | 10.0.26100.0 – < 10.0.26100.32690 | 10.0.26100.32690 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
GitHub 3 repositories
-
Semperis-Community/ResetNightmare ★ 226 · Aug 2, 2026
POC tool for ResetNightmare (CVE-2026-27912)
-
mihat2/ResetNightmare-impacket ★ 18 · Aug 8, 2026
CVE-2026-27912 (ResetNightmare) — Linux/impacket port of Semperis Community's Invoke-ResetNightmare PoC
-
oxstussz-eng/Kerberos-CVE-2026-27912 ★ 4 · Aug 14, 2026
PoC for CVE-2026-27912 - Windows Kerberos Elevation of Privilege (ResetNightmare). Unauthorized password reset via Kerberos flaw. For security research only.
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 3
- WID-SEC-2026-1104 Microsoft Windows: Mehrere Schwachstellen BSI CERT-Bund (WID) · Aug 27, 2026
- NCSC-2026-0119 Kwetsbaarheden verholpen in Microsoft Windows NCSC-NL (Netherlands) · Apr 15, 2026
- MSRC-CVE-2026-27912 Windows Kerberos Elevation of Privilege Vulnerability Microsoft Security Response Center · Apr 14, 2026
References
- Windows Kerberos Elevation of Privilege Vulnerability vendor-advisory patch