01 Record
CVE-2026-21525
Windows Remote Access Connection Manager Denial of Service Vulnerability
MediumKEVPUBLISHEDCNA: microsoft
CNA base score6.2 CVSS v3.xCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C
02 Description
Windows Remote Access Connection Manager Denial of Service Vulnerability
03 Exploitation and scoring
- Exploitation
- Exploited in the wild. Listed in the CISA Known Exploited Vulnerabilities catalog on 2026-02-10. Federal remediation due 2026-03-03.
- SSVC decision
- ExploitationactiveCISA reports credible evidence of active exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 4.86% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 91.9% of scored records. A rank, not a probability.
- NVD base score
- 6.2 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVD analysis status
- Analyzed. NVD last modified this record on 2026-06-17.
- Red Hat severity
- No Red Hat rating. Red Hat rates the CVEs that affect its products.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2026-02-10 17:51Z8 MO AGO
- Last updated
- 2026-08-19 16:26Z2 MO AGO
- Reserved
- 2025-12-30
- Assigning CNA
- microsoft
- Record state
- PUBLISHED
- Severity
- Medium (CVSS 6.2)
- CNA CVSS vector
- CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C
- Weaknesses
- CWE-476NULL Pointer DereferenceBase
- Data version
- 5.2
- Document digest
- e33b7fb7a3fda304217f116719319db9d664b7806ab017ce83fb1247cffd3b30
05 Affected products
VendorProductVersionsPlatforms
MicrosoftWindows 10 Version 21H210.0.19044.0 to < 10.0.19044.693732-bit Systems, ARM64-based Systems, x64-based Systems
MicrosoftWindows 10 Version 22H210.0.19045.0 to < 10.0.19045.693732-bit Systems, ARM64-based Systems, x64-based Systems
MicrosoftWindows 11 Version 24H210.0.26100.0 to < 10.0.26100.7840ARM64-based Systems, x64-based Systems
MicrosoftWindows Server 2012 (Server Core installation)6.2.9200.0 to < 6.2.9200.25923x64-based Systems
MicrosoftWindows Server 2012 R2 (Server Core installation)6.3.9600.0 to < 6.3.9600.23022x64-based Systems
MicrosoftWindows Server 2016 (Server Core installation)10.0.14393.0 to < 10.0.14393.8868x64-based Systems
MicrosoftWindows Server 2019 (Server Core installation)10.0.17763.0 to < 10.0.17763.8389x64-based Systems
MicrosoftWindows Server 2022, 23H2 Edition (Server Core installation)10.0.25398.0 to < 10.0.25398.2149x64-based Systems
MicrosoftWindows Server 2025 (Server Core installation)10.0.26100.0 to < 10.0.26100.32370x64-based Systems
06 References
- msrc.microsoft.comWindows Remote Access Connection Manager Denial of Service Vulnerabilityhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21525
- www.cisa.govhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21525
- www.vicarius.iohttps://www.vicarius.io/vsociety/posts/cve-2026-21525-detection-script-dos-vulnerability-in-windows-remote-access-connection-manager
- www.vicarius.iohttps://www.vicarius.io/vsociety/posts/cve-2026-21525-mitigation-script-dos-vulnerability-in-windows-remote-access-connection-manager