CVE-2026-21533

high

Description

Improper privilege management in Windows Remote Desktop allows an authorized attacker to elevate privileges locally.

References

https://www.vicarius.io/vsociety/posts/cve-2026-21533-mitigation-script-privilege-escalation-vulnerability-in-windows-remote-desktop

https://www.vicarius.io/vsociety/posts/cve-2026-21533-detection-script-privilege-escalation-vulnerability-in-windows-remote-desktop

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21533

https://www.malwarebytes.com/blog/news/2026/02/february-2026-patch-tuesday-includes-six-actively-exploited-zero-days

https://www.infosecurity-magazine.com/news/microsoft-six-zero-day-feb-2026/

https://www.helpnetsecurity.com/2026/02/11/february-2026-patch-tuesday/

https://thehackernews.com/2026/02/microsoft-patches-59-vulnerabilities.html

https://securityaffairs.com/187855/security/u-s-cisa-adds-microsoft-office-and-microsoft-windows-flaws-to-its-known-exploited-vulnerabilities-catalog.html

https://www.theregister.com/2026/02/10/microsofts_valentines_gift_to_admins/

https://www.securityweek.com/6-actively-exploited-zero-days-patched-by-microsoft-with-february-2026-updates/

https://www.cisa.gov/news-events/alerts/2026/02/10/cisa-adds-six-known-exploited-vulnerabilities-catalog

https://securityaffairs.com/187848/uncategorized/microsoft-patch-tuesday-security-updates-for-february-2026-fix-six-actively-exploited-zero-days.html

https://krebsonsecurity.com/2026/02/patch-tuesday-february-2026-edition/

https://cyberscoop.com/microsoft-patch-tuesday-february-2026/

https://www.tenable.com/blog/microsofts-february-2026-patch-tuesday-addresses-54-cves-cve-2026-21510-cve-2026-21513

https://github.com/stackviolator/ndaybench

https://github.com/fevar54/CVE-2026-21533_Scanner.py

https://github.com/richardpaimu34/CVE-2026-21533

https://github.com/washingtonmaister/CVE-2026-21533

https://github.com/elvin31thai/CVE-2026-21533

https://github.com/Pairs34/RDPVulnarableCheck

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21533

Details

Source: Mitre, NVD

Published: 2026-02-10

Updated: 2026-03-30

Known Exploited Vulnerability (KEV)

Risk Information

CVSS v2

Base Score: 6.8

Vector: CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C

Severity: Medium

CVSS v3

Base Score: 7.8

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Severity: High

EPSS

EPSS: 0.03846