CVE-2026-21533

CISA description

Microsoft Windows Remote Desktop Services contains an improper privilege management vulnerability that could allow an authorized attacker to elevate privileges locally.

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 & references

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21533
• https://nvd.nist.gov/vuln/detail/CVE-2026-21533

Where this lands in 800-53

Vulnerability data triggers these controls during assessment and continuous monitoring.

• RA-5 · Vulnerability Monitoring and Scanning
• SI-2 · Flaw Remediation
• CM-6 · Configuration Settings
• SI-7 · Software, Firmware, and Information Integrity
• CM-8 · System Component Inventory

External lookups

• NVD · CVE-2026-21533
• CVE.org · CVE-2026-21533
• CISA KEV catalog (canonical)