CVE-2026-20833 — Windows Kerberos Information Disclosure Vulnerability

Executive Summary

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

Overview

5.5

CVSS MEDIUM

Important

MS Severity

Not Exploited

MS Exploit Status

Less Likely

MS Exploit Likelihood

Category Information Disclosure

Released Jan 13 2026

Last Updated Jan 13 2026

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

EPSS Score 0.00363 — 0.28023 percentile

NVD CVSS 5.5 MEDIUM — matches MSRC

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

ATTACK VECTOR

Local

ATTACK COMPLEXITY

Low

PRIVILEGES REQUIRED

Low

USER INTERACTION

None

SCOPE

Unchanged

CONFIDENTIALITY

High

INTEGRITY

None

AVAILABILITY

None

EXPLOIT CODE MATURITY

Unproven

REMEDIATION LEVEL

Official Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 4.8

EPSS Score

0.00363

probability of exploitation in the next 30 days

0.28023 percentile - updated 2026-06-21

View on FIRST.org

Affected Products

13 affected products

Product	KB Article	Severity	Impact	Restart Required
Windows Server 2008 for 32-bit Systems Service Pack 2 5073697 (Monthly Rollup) 5073700 (Security Only) Important Information Disclosure 5071504 Base: 5.5 Temporal: 4.8 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 6.0.6003.23717 Yes None Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation) 5073697 (Monthly Rollup) 5073700 (Security Only) Important Information Disclosure 5071504 Base: 5.5 Temporal: 4.8 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 6.0.6003.23717 Yes None Windows Server 2008 for x64-based Systems Service Pack 2 5073697 (Monthly Rollup) 5073700 (Security Only) Important Information Disclosure 5071504 Base: 5.5 Temporal: 4.8 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 6.0.6003.23717 Yes None Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation) 5073697 (Monthly Rollup) 5073700 (Security Only) Important Information Disclosure 5071504 Base: 5.5 Temporal: 4.8 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 6.0.6003.23717 Yes None Windows Server 2008 R2 for x64-based Systems Service Pack 1 5073695 (Monthly Rollup) 5073699 (Security Only) Important Information Disclosure 5071501 Base: 5.5 Temporal: 4.8 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 6.1.7601.28117 Yes None Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) 5073695 (Monthly Rollup) 5073699 (Security Only) Important Information Disclosure 5071501 Base: 5.5 Temporal: 4.8 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 6.1.7601.28117 Yes None Windows Server 2012	`5073698 (Monthly Rollup)`	Important	Information Disclosure	Yes
Windows Server 2012 (Server Core installation)	`5073698 (Monthly Rollup)`	Important	Information Disclosure	Yes
Windows Server 2012 R2	`5073696 (Monthly Rollup)`	Important	Information Disclosure	Yes
Windows Server 2012 R2 (Server Core installation)	`5073696 (Monthly Rollup)`	Important	Information Disclosure	Yes
Windows Server 2016	`5073722 (Security Update)`	Important	Information Disclosure	Yes
Windows Server 2016 (Server Core installation)	`5073722 (Security Update)`	Important	Information Disclosure	Yes
Windows Server 2019	`5073723 (Security Update)`	Important	Information Disclosure	Yes
Windows Server 2019 (Server Core installation)	`5073723 (Security Update)`	Important	Information Disclosure	Yes
Windows Server 2022	`5073457 (Security Update)`	Important	Information Disclosure	Yes
Windows Server 2022 (Server Core installation)	`5073457 (Security Update)`	Important	Information Disclosure	Yes
Windows Server 2022, 23H2 Edition (Server Core installation)	`5073450 (Security Update)`	Important	Information Disclosure	Yes
Windows Server 2025	`5073379 (Security Update)`	Important	Information Disclosure	Yes
Windows Server 2025 (Server Core installation)	`5073379 (Security Update)`	Important	Information Disclosure	Yes

Patches

7 patches

Article	Type	Restart
`5073698`	Monthly Rollup	Yes
`5073696`	Monthly Rollup	Yes
`5073722`	Security Update	Yes
`5073723`	Security Update	Yes
`5073457`	Security Update	Yes
`5073450`	Security Update	Yes
`5073379`	Security Update	Yes

Known Exploits

No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.

Acknowledgments

Windows Authentication Platform team

References

MSRC Advisory MITRE NVD