CVE-2025-21299Public exploit

Credential Guard bypass via Kerberos name canonicalization

Published Jan 14, 2025 · Updated Jun 9, 2026

Security feature bypass in affected Microsoft Windows releases allows local users to extract Kerberos TGTs from Credential Guard. KerbGetFlagsForKdcReply recognizes only expected krbtgt name forms as protected, so an X.500 distinguished name causes a reusable TGT to leave the isolated LSA context. Exploitation requires local low-privilege access on a domain-joined host with Credential Guard enabled and exposes the current user's reusable TGT.

CVSS severity7.1
High
EPSS probability2.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Security feature bypass in affected Microsoft Windows releases allows local users to extract Kerberos TGTs from Credential Guard. KerbGetFlagsForKdcReply recognizes only expected krbtgt name forms as protected, so an X.500 distinguished name causes a reusable TGT to leave the isolated LSA context. Exploitation requires local low-privilege access on a domain-joined host with Credential Guard enabled and exposes the current user's reusable TGT.

The record

CVE
CVE-2025-21299
Published
Jan 14, 2025
Updated
Jun 9, 2026
Vendor
Microsoft
Product
Windows 10 Version 1507
Classifications
CWE-922, T1550.003
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 14, 2025CVE publishedPublication date reported by the CVE source.
  2. Jun 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.0.10240.0 <10.0.10240.20890

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Microsoft · Windows 10 Version 1507version=10.0.10240.0 <10.0.10240.20890
Microsoft · Windows Server 2019version=10.0.17763.0 <10.0.17763.6775
Microsoft · Windows Server 2025 (Server Core installation)version=10.0.26100.0 <10.0.26100.2894
Microsoft · Windows Server 2016 (Server Core installation)version=10.0.14393.0 <10.0.14393.7699
Microsoft · Windows 11, version 24H2version=10.0.26100.0 <10.0.26100.2894
Microsoft · Windows 10 Version 21H2version=10.0.19044.0 <10.0.19044.5371
Microsoft · Windows Server 2022, 23H2 Edition (Server Core installation)version=10.0.25398.0 <10.0.25398.1369
Microsoft · Windows Server 2016version=10.0.14393.0 <10.0.14393.7699
Microsoft · Windows 11 Version 22H3version=10.0.22631.0 <10.0.22631.4751
Microsoft · Windows 10 Version 22H2version=10.0.19045.0 <10.0.19045.5371
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.17763.0 <10.0.17763.6775
Microsoft · Windows 11 Version 23H2version=10.0.22631.0 <10.0.22631.4751
Microsoft · Windows 11, version 22H2version=10.0.22621.0 <10.0.22621.4751
Microsoft · Windows 10 Version 1607version=10.0.14393.0 <10.0.14393.7699
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.3091
Microsoft · Windows Server 2025version=10.0.26100.0 <10.0.26100.2894
Microsoft · Windows 10 Version 1809version=10.0.17763.0 <10.0.17763.6775

Published CVSS scores

7.8NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.1MicrosoftCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-922Insecure Storage of Sensitive Information
T1550.003Pass the Ticket

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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