Description
Use of a broken or risky cryptographic algorithm in Windows Kerberos allows an authorized attacker to disclose information locally.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Microsoft | Windows Server 2008 R2 Service Pack 1 | 6.1.7601.0 – < 6.1.7601.28117 | 6.1.7601.28117 |
| Microsoft | Windows Server 2008 R2 Service Pack 1 (Server Core installation) | 6.1.7601.0 – < 6.1.7601.28117 | 6.1.7601.28117 |
| Microsoft | Windows Server 2008 Service Pack 2 | 6.0.6003.0 – < 6.0.6003.23717 | 6.0.6003.23717 |
| Microsoft | Windows Server 2008 Service Pack 2 (Server Core installation) | 6.0.6003.0 – < 6.0.6003.23717 | 6.0.6003.23717 |
| Microsoft | Windows Server 2012 | 6.2.9200.0 – < 6.2.9200.25868 | 6.2.9200.25868 |
| Microsoft | Windows Server 2012 (Server Core installation) | 6.2.9200.0 – < 6.2.9200.25868 | 6.2.9200.25868 |
| Microsoft | Windows Server 2012 R2 | 6.3.9600.0 – < 6.3.9600.22968 | 6.3.9600.22968 |
| Microsoft | Windows Server 2012 R2 (Server Core installation) | 6.3.9600.0 – < 6.3.9600.22968 | 6.3.9600.22968 |
| Microsoft | Windows Server 2016 | 10.0.14393.0 – < 10.0.14393.8783 | 10.0.14393.8783 |
| Microsoft | Windows Server 2016 (Server Core installation) | 10.0.14393.0 – < 10.0.14393.8783 | 10.0.14393.8783 |
| Microsoft | Windows Server 2019 | 10.0.17763.0 – < 10.0.17763.8276 | 10.0.17763.8276 |
| Microsoft | Windows Server 2019 (Server Core installation) | 10.0.17763.0 – < 10.0.17763.8276 | 10.0.17763.8276 |
| Microsoft | Windows Server 2022 | 10.0.20348.0 – < 10.0.20348.4648 | 10.0.20348.4648 |
| Microsoft | Windows Server 2022, 23H2 Edition (Server Core installation) | 10.0.25398.0 – < 10.0.25398.2092 | 10.0.25398.2092 |
| Microsoft | Windows Server 2025 | 10.0.26100.0 – < 10.0.26100.32230 | 10.0.26100.32230 |
| Microsoft | Windows Server 2025 (Server Core installation) | 10.0.26100.0 – < 10.0.26100.32230 | 10.0.26100.32230 |
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 2 repositories
-
v-jfanca/cve-2026-20833-rc4-kerberos ★ 4 · Mar 15, 2026
Kerberos RC4 deprecation: detection, remediation and guidance (CVE-2026-20833)
-
AlMarWorld/KerberosAudit-PS ★ 0 · Jul 16, 2026
Kerberos audit for CVE-2026-20833
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 4
- NCSC-2026-0007 Kwetsbaarheden verholpen in Microsoft Windows NCSC-NL (Netherlands) · Apr 10, 2026
- WID-SEC-2026-0780 Samba: Schwachstelle ermöglicht Offenlegung von Informationen BSI CERT-Bund (WID) · Mar 18, 2026
- WID-SEC-2026-0083 Microsoft Windows : Mehrere Schwachstellen BSI CERT-Bund (WID) · Mar 2, 2026
- MSRC-CVE-2026-20833 Windows Kerberos Information Disclosure Vulnerability Microsoft Security Response Center · Jan 13, 2026
References
- Windows Kerberos Information Disclosure Vulnerability vendor-advisory patch