CVE-2026-21533
Windows Remote Desktop Services Elevation of Privilege Vulnerability
- Published
- Updated
- Reserved
- Assigned by
- microsoft
Description
Improper privilege management in Windows Remote Desktop allows an authorized attacker to elevate privileges locally.
Exploited in the wild
CISA lists this vulnerability in its Known Exploited Vulnerabilities catalog as Microsoft Windows Improper Privilege Management Vulnerability.
- Added
- 10 Feb 2026
- Fix due (US federal)
- 3 Mar 2026
- Used by ransomware
- Not known
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. CISA's SSVC rates its exploitation: it is being exploited.
Timeline
ID reserved
By microsoft
- 42 days later
· 42 days later
Published
Added to CISA KEV
Known exploited in the wild
- 6 months later
· 6 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| microsoftCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C |
| NVDNVD · Analyzed | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 4.3% · top 8.7% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: active · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Weakness
Affected products
Microsoft · Windows 10 Version 1607
- affected 10.0.14393.0 – < 10.0.14393.8868
Microsoft · Windows 10 Version 1809
- affected 10.0.17763.0 – < 10.0.17763.8389
Microsoft · Windows 10 Version 21H2
- affected 10.0.19044.0 – < 10.0.19044.6937
Microsoft · Windows 10 Version 22H2
- affected 10.0.19045.0 – < 10.0.19045.6937
Microsoft · Windows 11 version 22H3
- affected 10.0.22631.0 – < 10.0.22631.6649
Microsoft · Windows 11 Version 23H2
- affected 10.0.22631.0 – < 10.0.22631.6649
Microsoft · Windows 11 Version 24H2
- affected 10.0.26100.0 – < 10.0.26100.7840
Microsoft · Windows 11 Version 25H2
- affected 10.0.26200.0 – < 10.0.26200.7840
Microsoft · Windows 11 version 26H1
- affected 10.0.28000.0 – < 10.0.28000.1575
Microsoft · Windows 11 Version 26H1
- affected 10.0.28000.0 – < 10.0.28000.1575
Microsoft · Windows Server 2012
- affected 6.2.9200.0 – < 6.2.9200.25923
Microsoft · Windows Server 2012 (Server Core installation)
- affected 6.2.9200.0 – < 6.2.9200.25923
Microsoft · Windows Server 2012 R2
- affected 6.3.9600.0 – < 6.3.9600.23022
Microsoft · Windows Server 2012 R2 (Server Core installation)
- affected 6.3.9600.0 – < 6.3.9600.23022
Microsoft · Windows Server 2016
- affected 10.0.14393.0 – < 10.0.14393.8868
Microsoft · Windows Server 2016 (Server Core installation)
- affected 10.0.14393.0 – < 10.0.14393.8868
Microsoft · Windows Server 2019
- affected 10.0.17763.0 – < 10.0.17763.8389
Microsoft · Windows Server 2019 (Server Core installation)
- affected 10.0.17763.0 – < 10.0.17763.8389
Microsoft · Windows Server 2022
- affected 10.0.20348.0 – < 10.0.20348.4773
Microsoft · Windows Server 2022, 23H2 Edition (Server Core installation)
- affected 10.0.25398.0 – < 10.0.25398.2149
Microsoft · Windows Server 2025
- affected 10.0.26100.0 – < 10.0.26100.32370
Microsoft · Windows Server 2025 (Server Core installation)
- affected 10.0.26100.0 – < 10.0.26100.32370
References (4)
- Windows Remote Desktop Services Elevation of Privilege Vulnerability (opens in a new tab)vendor-advisorypatch
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21533 (opens in a new tab)government-resource
- https://www.vicarius.io/vsociety/posts/cve-2026-21533-detection-script-privilege-escalation-vulnerability-in-windows-remote-desktop (opens in a new tab)
- https://www.vicarius.io/vsociety/posts/cve-2026-21533-mitigation-script-privilege-escalation-vulnerability-in-windows-remote-desktop (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- CISA KEV catalog (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-21533)Record last updated .