CVE-2026-21525Known exploitationHinoki check available

Local service crash via null pointer dereference

Published Feb 10, 2026 · Updated Feb 10, 2026

Null pointer dereference in Microsoft Windows Remote Access Connection Manager allows local users to crash the service without authentication. Microsoft has not disclosed the affected function, input path, or operation that permits attacker-controlled input to reach a null pointer. Local execution is required; the reported consequence is an availability-only interruption of remote-access and VPN connections.

CVSS severity6.2
Medium
EPSS probability5.04%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Null pointer dereference in Microsoft Windows Remote Access Connection Manager allows local users to crash the service without authentication. Microsoft has not disclosed the affected function, input path, or operation that permits attacker-controlled input to reach a null pointer. Local execution is required; the reported consequence is an availability-only interruption of remote-access and VPN connections.

The record

CVE
CVE-2026-21525
Published
Feb 10, 2026
Updated
Feb 10, 2026
Vendor
Microsoft
Product
Windows Server 2019
Classifications
CWE-476, T1499
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 10, 2026Exploitation reportedCISA Known Exploited Vulnerabilities catalog entry
  2. Feb 10, 2026CVE publishedPublication date reported by the CVE source.
  3. Feb 10, 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=10.0.17763.0 <10.0.17763.8389

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Microsoft · Windows Server 2019version=10.0.17763.0 <10.0.17763.8389
Microsoft · Windows Server 2025 (Server Core installation)version=10.0.26100.0 <10.0.26100.32370
Microsoft · Windows 11, version 25H2version=10.0.26200.0 <10.0.26200.7840
Microsoft · Windows Server 2016 (Server Core installation)version=10.0.14393.0 <10.0.14393.8868
Microsoft · Windows 11, version 24H2version=10.0.26100.0 <10.0.26100.7840
Microsoft · Windows Server 2012 (Server Core installation)version=6.2.9200.0 <6.2.9200.25923
Microsoft · Windows Server 2012version=6.2.9200.0 <6.2.9200.25923
Microsoft · Windows 10 Version 21H2version=10.0.19044.0 <10.0.19044.6937
Microsoft · Windows Server 2022, 23H2 Edition (Server Core installation)version=10.0.25398.0 <10.0.25398.2149
Microsoft · Windows Server 2016version=10.0.14393.0 <10.0.14393.8868
Microsoft · Windows 11 Version 22H3version=10.0.22631.0 <10.0.22631.6649
Microsoft · Windows 10 Version 22H2version=10.0.19045.0 <10.0.19045.6937
Microsoft · Windows Server 2012 R2 (Server Core installation)version=6.3.9600.0 <6.3.9600.23022
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.17763.0 <10.0.17763.8389
Microsoft · Windows 11, version 26H1version=10.0.28000.0 <10.0.28000.1575
Microsoft · Windows 11 Version 23H2version=10.0.22631.0 <10.0.22631.6649
Microsoft · Windows 10 Version 1607version=10.0.14393.0 <10.0.14393.8868
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.4773
Microsoft · Windows Server 2025version=10.0.26100.0 <10.0.26100.32370
Microsoft · Windows 10 Version 1809version=10.0.17763.0 <10.0.17763.8389
Microsoft · Windows Server 2012 R2version=6.3.9600.0 <6.3.9600.23022

Published CVSS scores

6.2MicrosoftCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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

Reported exploitation

Technologies

Your stack

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Your stack

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