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NVD / CVE Program· CNA microsoft

CVE-2026-20833: Windows Kerberos Information Disclosure Vulnerability

Noroxi assessment

Priority: Monitor (action score 22/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.53% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Windows Server 2008 for 32-bit Systems Service Pack 2 6.0.6003.23717; Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation) 6.0.6003.23717; Windows Server 2008 for x64-based Systems Service Pack 2 6.0.6003.23717.

Low priority for now. Upgrade to Windows Server 2008 for 32-bit Systems Service Pack 2 6.0.6003.23717; Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation) 6.0.6003.23717; Windows Server 2008 for x64-based Systems Service Pack 2 6.0.6003.23717 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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

MediumCVSS 5.5 · v3.1—Proof of concept Fix available
Published
Jan 13, 2026
Updated
Jul 30, 2026
EPSS
0.5% · 45th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · microsoft
5.5
NVD has not scored this yet; the score shown is the CNA’s.

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-20833

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
microsoftwindows server 2008
microsoftwindows server 2012
microsoftwindows server 2016
microsoftwindows server 2019
microsoftwindows server 2022
microsoftwindows server 2022 23h2
microsoftwindows server 2025

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When you'll hear from us

  • when a new CVE affecting this product is published
  • when a record in your stack enters KEV or gets exploit code

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

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Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

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Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • microsoft windows server 2008all versions
  • microsoft windows server 2008r2
  • microsoft windows server 2012all versions
  • microsoft windows server 2012r2
  • microsoft windows server 2016before 10.0.14393.8783
  • microsoft windows server 2019before 10.0.17763.8276
  • microsoft windows server 2022before 10.0.20348.4648
  • microsoft windows server 2022 23h2before 10.0.25398.2092
  • microsoft windows server 2025before 10.0.26100.32230

Versions reported by the vendor

Affected version ranges reported by the assigning authority (microsoft). Independent of NVD's CPE analysis and usually ahead of it.

  • Microsoft Windows Server 2008 R2 Service Pack 1

    • 6.1.7601.0 and later · before 6.1.7601.28117affected

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

    • 6.1.7601.0 and later · before 6.1.7601.28117affected

  • Microsoft Windows Server 2008 Service Pack 2

    • 6.0.6003.0 and later · before 6.0.6003.23717affected

  • Microsoft Windows Server 2008 Service Pack 2 (Server Core installation)

    • 6.0.6003.0 and later · before 6.0.6003.23717affected

  • Microsoft Windows Server 2012

    • 6.2.9200.0 and later · before 6.2.9200.25868affected

  • Microsoft Windows Server 2012 (Server Core installation)

    • 6.2.9200.0 and later · before 6.2.9200.25868affected

  • Microsoft Windows Server 2012 R2

    • 6.3.9600.0 and later · before 6.3.9600.22968affected

  • Microsoft Windows Server 2012 R2 (Server Core installation)

    • 6.3.9600.0 and later · before 6.3.9600.22968affected

  • Microsoft Windows Server 2016

    • 10.0.14393.0 and later · before 10.0.14393.8783affected

  • Microsoft Windows Server 2016 (Server Core installation)

    • 10.0.14393.0 and later · before 10.0.14393.8783affected

  • Microsoft Windows Server 2019

    • 10.0.17763.0 and later · before 10.0.17763.8276affected

  • Microsoft Windows Server 2019 (Server Core installation)

    • 10.0.17763.0 and later · before 10.0.17763.8276affected

Same product

microsoft: all records

Other highest-scoring records for the same primary product.

  • CVE-2020-1350A remote code execution vulnerability exists in Windows Domain Name System servers when they fail to properly handle requests, aka 'Windows KEV
    99Now
  • CVE-2020-1040A remote code execution vulnerability exists when Hyper-V RemoteFX vGPU on a host server fails to properly validate input from an authenticaKEV
    68This week
  • CVE-2009-3103Array index error in the SMBv2 protocol implementation in srv2.sys in Microsoft Windows Vista Gold, SP1, and SP2, Windows Server 2008 Gold a
    68This week

Published before and after this one in the same product

  • ← EarlierCVE-2025-54113Sep 9, 2025 · Windows Routing and Remote Access Service (RRAS) Remote Code Execution Vulnerability
    35Monitor
  • ← EarlierCVE-2025-55225Sep 9, 2025 · Windows Routing and Remote Access Service (RRAS) Information Disclosure Vulnerability
    26Monitor
  • ← EarlierCVE-2026-0386Jan 13, 2026 · Windows Deployment Services Remote Code Execution Vulnerability
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Windows Server 2008 for 32-bit Systems Service Pack 26.0.6003.23717 · KB5073697Microsoft (MSRC)
Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)6.0.6003.23717 · KB5073697Microsoft (MSRC)
Windows Server 2008 for x64-based Systems Service Pack 26.0.6003.23717 · KB5073697Microsoft (MSRC)
Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)6.0.6003.23717 · KB5073697Microsoft (MSRC)
Windows Server 2008 R2 for x64-based Systems Service Pack 16.1.7601.28117 · KB5073695Microsoft (MSRC)
Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)6.1.7601.28117 · KB5073695Microsoft (MSRC)
Windows Server 20126.2.9200.25868 · KB5073698Microsoft (MSRC)
Windows Server 2012 (Server Core installation)6.2.9200.25868 · KB5073698Microsoft (MSRC)
Windows Server 2012 R26.3.9600.22968 · KB5073696Microsoft (MSRC)
Windows Server 2012 R2 (Server Core installation)6.3.9600.22968 · KB5073696Microsoft (MSRC)
Windows Server 201610.0.14393.8783 · KB5073722Microsoft (MSRC)
Windows Server 2016 (Server Core installation)10.0.14393.8783 · KB5073722Microsoft (MSRC)
Windows Server 201910.0.17763.8276 · KB5073723Microsoft (MSRC)
Windows Server 2019 (Server Core installation)10.0.17763.8276 · KB5073723Microsoft (MSRC)
Windows Server 202210.0.20348.4648 · KB5073457Microsoft (MSRC)
Windows Server 2022 (Server Core installation)10.0.20348.4648 · KB5073457Microsoft (MSRC)
Windows Server 2022, 23H2 Edition (Server Core installation)10.0.25398.2092 · KB5073450Microsoft (MSRC)
Windows Server 202510.0.26100.32230 · KB5073379Microsoft (MSRC)
Windows Server 2025 (Server Core installation)10.0.26100.32230 · KB5073379Microsoft (MSRC)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×2

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:32026-03-15
Proof-of-concept repository on GitHubstars:02026-07-16

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. First PoC+60 d
  3. TodayNov 5, 2026+296 d

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
none
Availability
none
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
None
Availability impact
None

Weakness class (CWE)

CWE-327 · Use of a Broken or Risky Cryptographic Algorithm

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records