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CVE-2026-20833: CWE-327: Use of a Broken or Risky Cryptographic Algorithm in Microsoft Windows Server 2008 R2 Service Pack 1

0
Medium
VulnerabilityCVE-2026-20833cvecve-2026-20833cwe-327
Published: 01/13/2026 (01/13/2026, 17:56:23 UTC)
Source: CVE Database V5
Vendor/Project: Microsoft
Product: Windows Server 2008 R2 Service Pack 1

Description

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

CVSS v3.1

Score 5.5medium

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None
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

Affected software

Microsoft

Windows Server 2008 R2 Service Pack 1

Affected versions
>=6.1.7601.0 <6.1.7601.28117

Microsoft

Windows Server 2008 R2 Service Pack 1 (Server Core installation)

Affected versions
>=6.1.7601.0 <6.1.7601.28117

Microsoft

Windows Server 2008 Service Pack 2

Affected versions
>=6.0.6003.0 <6.0.6003.23717

Microsoft

Windows Server 2008 Service Pack 2 (Server Core installation)

Affected versions
>=6.0.6003.0 <6.0.6003.23717

Microsoft

Windows Server 2012

Affected versions
>=6.2.9200.0 <6.2.9200.25868

Microsoft

Windows Server 2012 (Server Core installation)

Affected versions
>=6.2.9200.0 <6.2.9200.25868

Microsoft

Windows Server 2012 R2

Affected versions
>=6.3.9600.0 <6.3.9600.22968

Microsoft

Windows Server 2012 R2 (Server Core installation)

Affected versions
>=6.3.9600.0 <6.3.9600.22968

Microsoft

Windows Server 2016

Affected versions
>=10.0.14393.0 <10.0.14393.8783

Microsoft

Windows Server 2016 (Server Core installation)

Affected versions
>=10.0.14393.0 <10.0.14393.8783

Microsoft

Windows Server 2019

Affected versions
>=10.0.17763.0 <10.0.17763.8276

Microsoft

Windows Server 2019 (Server Core installation)

Affected versions
>=10.0.17763.0 <10.0.17763.8276

Microsoft

Windows Server 2022

Affected versions
>=10.0.20348.0 <10.0.20348.4648

Microsoft

Windows Server 2022, 23H2 Edition (Server Core installation)

Affected versions
>=10.0.25398.0 <10.0.25398.2092

Microsoft

Windows Server 2025

Affected versions
>=10.0.26100.0 <10.0.26100.32230

Microsoft

Windows Server 2025 (Server Core installation)

Affected versions
>=10.0.26100.0 <10.0.26100.32230

AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 07/30/2026, 23:55:48 UTC

Technical Analysis

This vulnerability (CVE-2026-20833) concerns the use of a broken or risky cryptographic algorithm within the Windows Kerberos authentication protocol on Windows Server 2008 R2 SP1 (version 6.1.7601.0). An authorized attacker with local access can exploit this weakness to disclose information. The issue is classified under CWE-327, indicating improper use of cryptographic algorithms. Microsoft has published an official fix to remediate the vulnerability.

Potential Impact

An authorized local attacker can disclose sensitive information due to the use of a weak cryptographic algorithm in Windows Kerberos. The vulnerability does not affect integrity or availability but impacts confidentiality. There are no known exploits in the wild at this time.

Mitigation Recommendations

An official fix is available from Microsoft. Users should apply the security update referenced in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20833 to remediate this vulnerability.

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Technical Details

Data Version
5.2
Assigner Short Name
microsoft
Date Reserved
2025-12-03T05:54:20.375Z
Cvss Version
3.1
State
PUBLISHED
Remediation Level
official-fix
Vendor Advisory Urls
[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20833","vendor":"Microsoft"}]

Threat ID: 69668adda60475309f9adff0

Added to database: 01/13/2026, 18:11:41 UTC

Last enriched: 07/30/2026, 23:55:48 UTC

Last updated: 09/10/2026, 22:26:03 UTC

Views: 250

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