CVE-2026-20833

MEDIUM

Windows Server 2008 and later - Information Disclosure via Broken Cryptographic Algorithm in Kerberos

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 2 public exploits for CVE-2026-20833. PoCs published by AlMarWorld, v-jfanca.

AI-analyzed exploit summary This repository provides a PowerShell-based auditing tool for Kerberos authentication events in Active Directory environments. It collects and analyzes Kerberos-related security events (IDs 4768, 4769, 4771) from domain controllers but does not exploit any vulnerability.

Description

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

Exploits (2)

nomisec SCANNER
by AlMarWorld · poc
https://github.com/AlMarWorld/KerberosAudit-PS

This repository provides a PowerShell-based auditing tool for Kerberos authentication events in Active Directory environments. It collects and analyzes Kerberos-related security events (IDs 4768, 4769, 4771) from domain controllers but does not exploit any vulnerability.

Classification
Scanner 98%
Attack Type
Info Leak
Complexity
Moderate
Reliability
Reliable
Target: Microsoft Active Directory (Kerberos authentication events)
Auth required
Prerequisites: Active Directory environment access · Permissions to query domain controllers and read Security event logs · PowerShell with ActiveDirectory module
mistral-large-3 · analyzed Jul 16, 2026 Full analysis →
nomisec WRITEUP
by v-jfanca · poc
https://github.com/v-jfanca/cve-2026-20833-rc4-kerberos

This repository provides comprehensive technical documentation and operational guidance for detecting and remediating RC4 usage in Kerberos authentication, as part of Microsoft's security changes for CVE-2026-20833. It includes PowerShell scripts, Power BI dashboards, and detailed analysis of Kerberos encryption usage.

Classification
Writeup 95%
Attack Type
Other
Complexity
Moderate
Reliability
Reliable
Target: Microsoft Active Directory Kerberos
No auth needed
Prerequisites: Access to Domain Controller event logs · PowerShell execution rights · Power BI for dashboard visualization
mistral-large-3 · analyzed Mar 15, 2026 Full analysis →

References (1)

Core 1
Core References

Scores

CVSS v3 5.5
EPSS 0.0048
EPSS Percentile 39.0%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-327
Status published
Products (25)
Microsoft/Windows Server 2008 R2 Service Pack 1 6.1.7601.0 - 6.1.7601.28117
Microsoft/Windows Server 2008 R2 Service Pack 1 (Server Core installation) 6.1.7601.0 - 6.1.7601.28117
Microsoft/Windows Server 2008 Service Pack 2 6.0.6003.0 - 6.0.6003.23717
Microsoft/Windows Server 2008 Service Pack 2 (Server Core installation) 6.0.6003.0 - 6.0.6003.23717
Microsoft/Windows Server 2012 6.2.9200.0 - 6.2.9200.25868
Microsoft/Windows Server 2012 (Server Core installation) 6.2.9200.0 - 6.2.9200.25868
Microsoft/Windows Server 2012 R2 6.3.9600.0 - 6.3.9600.22968
Microsoft/Windows Server 2012 R2 (Server Core installation) 6.3.9600.0 - 6.3.9600.22968
Microsoft/Windows Server 2016 10.0.14393.0 - 10.0.14393.8783
Microsoft/Windows Server 2016 (Server Core installation) 10.0.14393.0 - 10.0.14393.8783
... and 15 more
Published Jan 13, 2026
Tracked Since Feb 18, 2026