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
Source :
[email protected]
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.
CVSS Scores
| 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
- Install relevant Windows security updates.
- Install applicable cumulative updates.
Public PoC/Exploit Available at Github
CVE-2026-20833 has a 10 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:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-20833
weaknesses.
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).
A new build-review tool for windows hosts with exploitability mapping in-mind.
PowerShell
Check your servers and accounts RC4 posture
PowerShell
Comprehensive reference for Kerberos authentication in Microsoft Active Directory — protocol internals, security configuration, and attack techniques.
active-directory authentication blue-team cybersecurity kerberos penetration-testing red-team windows-security
CSS HTML Makefile JavaScript
Security research and exploit development: vulnerability analysis, exploit chain implementation, post-exploitation tradecraft, and defensive assessment tooling. Covers browser engines, persistence mechanisms, credential harvesting, C2 patterns, and AI-accelerated attack automation.
ai-security browser-security credential-harvesting cve exploit-development post-exploitation proof-of-concept red-team reverse-engineering security-research streamlit vulnerability-analysis worm
Shell HTML JavaScript Batchfile PowerShell Python Makefile Rust C YARA
None
PowerShell
Kerberos RC4 deprecation: detection, remediation and guidance (CVE-2026-20833)
PowerShell
None
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
PowerShell toolkit for assessing DES/RC4 Kerberos encryption in Active Directory. Detects weak encryption across domain controllers, trusts, and event logs. Built for the January 2026 update and July 2026 RC4 removal deadlines.
active-directory ad-security aes compliance cybersecurity des domain-controller encryption kerberos powershell rc4 security-assessment security-audit windows-server windows-server-2025
PowerShell
📡 PoC auto collect from GitHub. ⚠️ Be careful Malware.
security cve exploit poc vulnerability
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.
-
CybersecurityNews
Microsoft Confirms Windows Servers Enter Reboot Loops Following April Patches
Microsoft has confirmed a critical known issue affecting Windows Server 2025 domain controllers following the deployment of the April 2026 Patch Tuesday cumulative update, KB5082063, where affected se ... Read more
-
Help Net Security
Samba 4.24.0 ships Kerberos hardening and a CVE fix for domain encryption defaults
Samba 4.24.0 arrived carrying a set of Kerberos security changes aimed at Active Directory deployments. The release fixes a vulnerability, extends audit coverage for sensitive AD attributes, and intro ... Read more
-
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
-
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
-
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
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