Home/CVE/Microsoft Windows NULL Pointer Dereference Vulnerability
CVE

CVE-2026-21525

Microsoft Windows NULL Pointer Dereference Vulnerability

Null pointer dereference in Windows Remote Access Connection Manager allows an unauthorized attacker to deny service locally.

MEDIUM · CVSS 6.2 ⚠ CISA KEV EPSS 0.09386
Act now
  • Listed on CISA KEV (known exploited in the wild)
  • SSVC exploitation status: active
  • EPSS percentile: top 7% of all CVEs by exploitation likelihood
Sigma rules0 YARA rules0
⬢

Required Remediation

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

⬡

Weakness Classification

CWE-476NULL Pointer Dereference
▤

Affected Products & Versions

13
microsoft windows 10 1607< 10.0.14393.8868
microsoft windows 10 1809< 10.0.17763.8389
microsoft windows 10 21h2< 10.0.19044.6937
microsoft windows 10 22h2< 10.0.19045.6937
microsoft windows 11 23h2< 10.0.22631.6649
microsoft windows 11 24h2< 10.0.26100.7781
microsoft windows 11 25h2< 10.0.26200.7781
microsoft windows server 2012all versions
▣

Scoring & Timeline

6.2
MEDIUM · CVSS v3.1 · secure@microsoft.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD10 Feb 2026 · 06:16 PM
CVSS VectorCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
SSVC triage · cisa-vulnrichment
Exploitation
active
Automatable
no
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
⚑

Vendor Advisories

2
msrcCVE-2026-21525Denial of Service
cisaKEV-CVE-2026-21525
🔗

References & Sources

3
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://www.vicarius.io/vsociety/posts/cve-2026-21525-detection-script-dos-vulnerability-in-windows-remote-access-connection-managerThird Party Advisory
https://www.vicarius.io/vsociety/posts/cve-2026-21525-mitigation-script-dos-vulnerability-in-windows-remote-access-connection-managerMitigationThird Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21525US Government Resource
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