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Medium severity · published Feb 10, 2026
CVE-2026-21525
Windows Remote Access Connection Manager Denial of Service Vulnerability
In wildKEV
6.2
CVSS
4.9%
EPSS
Yes
On KEV
Description
Null pointer dereference in Windows Remote Access Connection Manager allows an unauthorized attacker to deny service locally.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)4.9% · higher than 92% of CVEs
Exploited in the wildYes
CISA KEVListed Feb 10, 2026
Federal remediation dueMar 3, 2026
Ransomware campaign useNot known
Affected products
Which versions
WI
Windows · Microsoft
All versions, or not specified · source: KEV
W1
Windows 10 Version 1607 · Microsoft
10.0.14393.0 before 10.0.14393.8868 · source: vendor
W1
Windows 10 Version 1809 · Microsoft
10.0.17763.0 before 10.0.17763.8389 · source: vendor
W1
Windows 10 Version 21H2 · Microsoft
10.0.19044.0 before 10.0.19044.6937 · source: vendor
W1
Windows 10 Version 22H2 · Microsoft
10.0.19045.0 before 10.0.19045.6937 · source: vendor
W1
Windows 11 Version 23H2 · Microsoft
10.0.22631.0 before 10.0.22631.6649 · source: vendor
W1
Windows 11 Version 24H2 · Microsoft
10.0.26100.0 before 10.0.26100.7840 · source: vendor
W1
Windows 11 Version 25H2 · Microsoft
10.0.26200.0 before 10.0.26200.7840 · source: vendor
W1
Windows 11 version 22H3 · Microsoft
10.0.22631.0 before 10.0.22631.6649 · source: vendor
W1
Windows 11 version 26H1 · Microsoft
10.0.28000.0 before 10.0.28000.1575; 10.0.28000.0 before 10.0.28000.1575 · source: vendor
WS
Windows Server 2012 · Microsoft
6.2.9200.0 before 6.2.9200.25923 · source: vendor, NVD
WS
Windows Server 2012 (Server Core installation) · Microsoft
6.2.9200.0 before 6.2.9200.25923 · source: vendor
In the news
VulnerabilityMedium
[CISA KEV] CVE-2026-21525: Microsoft Windows - Microsoft Windows NULL Pointer Dereference Vulnerability
Microsoft Windows Remote Access Connection Manager contains a NULL pointer dereference that could allow an unauthorized attacker to deny service locally.
WIWindowsCVE-2026-21525
Feb 10, 2026·CISA KEV
Affected product
WI
Windows
Microsoft
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-21525
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-21525
CISA KEV catalogue
https://www.cisa.gov/known-exploited-vulnerabilities-catalog
vendor-advisory
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21525
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