5.5
MEDIUM CVSS 3.1
CVE-2026-20833
Windows Kerberos Information Disclosure Vulnerability
Description

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

INFO

Published Date :

Jan. 13, 2026, 6:16 p.m.

Last Modified :

Jan. 15, 2026, 2:40 p.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-20833 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Microsoft windows_server_2008
2 Microsoft windows_server_2012
3 Microsoft windows_server_2016
4 Microsoft windows_server_2019
5 Microsoft windows_server_2022
6 Microsoft windows_server_2022_23h2
7 Microsoft windows_server_23h2
8 Microsoft windows_server_2012_r2
9 Microsoft windows_server_2008_r2
10 Microsoft windows_server_2008_sp2
11 Microsoft windows_server_2025
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM f38d906d-7342-40ea-92c1-6c4a2c6478c8
CVSS 3.1 MEDIUM [email protected]
Solution
Apply available security updates to mitigate the Kerberos information disclosure vulnerability.
  • Install relevant Windows security updates.
  • Install applicable cumulative updates.
Public PoC/Exploit Available at Github

CVE-2026-20833 has a 1 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-20833.

URL Resource
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20833 Vendor Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-20833 is associated with the following CWEs:

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

AD April ’26 Check0r is a read-only PowerShell tool to assess on-prem AD for the April 2026 Kerberos RC4→AES change. It inventories SPN accounts, flags risky msDS-SupportedEncryptionTypes/KDC overrides, and collects DC System readiness events (201–209) to predict breakage and guide fixes.

PowerShell

Updated: 3 days, 18 hours ago
4 stars 0 fork 0 watcher
Born at : Jan. 29, 2026, 8:48 a.m. This repo has been linked 1 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-20833 vulnerability anywhere in the article.

  • Zero Day Initiative
The January 2026 Security Update Review

I may be in Tokyo preparing for Pwn2Own Automotive, but that doesn’t stop patch Tuesday from coming. Put aside you broken New Year’s resolutions for just a moment as we review the latest security patc ... Read more

Published Date: Jan 13, 2026 (2 weeks, 6 days ago)
  • BleepingComputer
Microsoft January 2026 Patch Tuesday fixes 3 zero-days, 114 flaws

Today is Microsoft's January 2026 Patch Tuesday with security updates for 114 flaws, including one actively exploited and two publicly disclosed zero-day vulnerabilities.This Patch Tuesday also addres ... Read more

Published Date: Jan 13, 2026 (2 weeks, 6 days ago)
  • CybersecurityNews
Microsoft Patch Tuesday January 2026 – 114 Vulnerabilities Fixed Including 3 Zero-days

CVE-2026-20822Windows Graphics Component Elevation of Privilege VulnerabilityElevation of PrivilegeCVE-2026-20876Windows Virtualization-Based Security (VBS) Enclave Elevation of Privilege Vulnerabilit ... Read more

Published Date: Jan 13, 2026 (2 weeks, 6 days ago)

The following table lists the changes that have been made to the CVE-2026-20833 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Jan. 15, 2026

    Action Type Old Value New Value
    Added CPE Configuration OR *cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:* *cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:x64:* *cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:x86:* *cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:* versions up to (excluding) 10.0.14393.8783 *cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:* versions up to (excluding) 10.0.17763.8276 *cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:* versions up to (excluding) 10.0.20348.4648 *cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:*:*:*:* versions up to (excluding) 10.0.25398.2092 *cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:* versions up to (excluding) 10.0.26100.32230
    Added Reference Type Microsoft Corporation: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20833 Types: Vendor Advisory
  • New CVE Received by [email protected]

    Jan. 13, 2026

    Action Type Old Value New Value
    Added Description Use of a broken or risky cryptographic algorithm in Windows Kerberos allows an authorized attacker to disclose information locally.
    Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
    Added CWE CWE-327
    Added Reference https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20833
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 5.5
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact