CVE-2026-20833: Windows Kerberos Information Disclosure Vulnerability

Overview

Severity
Medium (CVSS 5.5)
CVSS Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
Category
Information Disclosure
Exploit Status
Not Exploited
Exploitation Likelihood
Less Likely
Patch Tuesday
2026-Jan
Released
2026-01-13
EPSS Score
0.03% (percentile: 8.3%)

Description

Use of a broken or risky cryptographic algorithm in Windows Kerberos allows an authorized attacker to disclose information locally.

FAQ

Are there other steps that need to be done to protect from exploitation of this vulnerability? Yes, please see How to manage Kerberos protocol changes related to CVE-2026-20833 for more information about how to protect from this vulnerability. What type of information could be disclosed by this vulnerability? The type of information that could be disclosed if an attacker successfully exploited this vulnerability is secrets or privileged information belonging to the user of the affected application.

Detection & Weaponization (1 sources)

Maturity: Exploit

  • GitHub PoC: 1 repositories

Affected Products (19)

Windows

  • Windows Server 2019
  • Windows Server 2019 (Server Core installation)
  • Windows Server 2022
  • Windows Server 2022 (Server Core installation)
  • Windows Server 2025 (Server Core installation)
  • Windows Server 2022, 23H2 Edition (Server Core installation)
  • Windows Server 2025
  • Windows Server 2016
  • Windows Server 2016 (Server Core installation)

ESU

  • Windows Server 2008 for 32-bit Systems Service Pack 2
  • Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
  • Windows Server 2008 for x64-based Systems Service Pack 2
  • Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)
  • Windows Server 2008 R2 for x64-based Systems Service Pack 1
  • Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)
  • Windows Server 2012
  • Windows Server 2012 (Server Core installation)
  • Windows Server 2012 R2
  • Windows Server 2012 R2 (Server Core installation)

Security Updates (11)

Acknowledgments

Windows Authentication Platform team

Revision History

  • 2026-01-13: Information published.