CVEvulnerability
CVE-2026-21533
CISA Known Exploited Vulnerability
Microsoft Windows Improper Privilege Management Vulnerability — Microsoft Windows
Microsoft Windows Remote Desktop Services contains an improper privilege management vulnerability that could allow an authorized attacker to elevate privileges locally.
- Added to KEV
- 2026-02-10
- Remediation due
- 2026-03-03
- Ransomware use
- Unknown
- Required action
- Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- Notes
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21533 ; https://nvd.nist.gov/vuln/detail/CVE-2026-21533
- Status
- Analyzed
- Published
- 2026-02-10
- Last modified
- 2026-06-17
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 7.8 HIGH — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weaknesses
- CWE-269
Description
Improper privilege management in Windows Remote Desktop allows an authorized attacker to elevate privileges locally.
Affected configurations
• 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 2012
• microsoft windows server 2012 r2
• microsoft windows server 2016 (< 10.0.14393.8868)
• microsoft windows server 2019 (< 10.0.17763.8389)
• microsoft windows server 2022 (< 10.0.20348.4711)
• microsoft windows server 2022 23h2 (< 10.0.25398.2149)
• microsoft windows server 2025 (< 10.0.26100.32313)
Related
Weakness · CWE (1)
- CWE-269 Improper Privilege Management weakness
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21533 Vendor Advisory
- https://www.vicarius.io/vsociety/posts/cve-2026-21533-detection-script-privilege-escalation-vulnerability-in-windows-remote-desktop Third Party Advisory
- https://www.vicarius.io/vsociety/posts/cve-2026-21533-mitigation-script-privilege-escalation-vulnerability-in-windows-remote-desktop Mitigation, Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21533 US Government Resource