CVE-2026-21533

CRITICALNVD 7.89.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2026-02-10), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 7.8 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, ghsa, nvd
Trending — 5 sources updated this weekExploited in the wild
9.0EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 4%CVSS: 7.8Exploit: cisa kev · ssvc activeExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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

CVSS v3
7.8
EG Score
9.0(high)
EG Risk
81(Attend)
EG Risk 81/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity90% × 45%
Exploitation100% × 40%
Automatability0% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
4%
EPSS %ILE
89%
KEV
⚠ Exploited

Published

February 10, 2026

Last Modified

June 17, 2026

Advisory Details (4)

Auto-updated Jun 3, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: microsoft, cisa.
cisa Patch Available🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

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

CVE-2026-21533 Mitigation Script - Privilege Escalation Vulnerability in Windows Remote Desktop - vsociety

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

CVE-2026-21533 Detection Script - Privilege Escalation Vulnerability in Windows Remote Desktop - vsociety

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

Security Update Guide - Microsoft Security Response Center

Security Update Guide - Microsoft Security Response Center. Patch available via Microsoft Security Update

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

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 91× in last 7d / 383× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 811 total refreshes for this CVE.

  1. 2026-08-01 06:48 UTCEG score recompute
  2. 2026-08-01 06:48 UTCVendor advisory
  3. 2026-08-01 06:48 UTCGHSA enrichment
  4. 2026-08-01 04:15 UTCEPSS rescore
  5. 2026-08-01 02:48 UTCVendor advisory
  6. 2026-08-01 02:47 UTCGHSA enrichment
  7. 2026-07-31 22:47 UTCVendor advisory
  8. 2026-07-31 22:46 UTCGHSA enrichment
  9. 2026-07-31 18:45 UTCVendor advisory
  10. 2026-07-31 18:45 UTCGHSA enrichment
  11. 2026-07-31 14:45 UTCVendor advisory
  12. 2026-07-31 14:44 UTCGHSA enrichment
  13. 2026-07-31 10:45 UTCVendor advisory
  14. 2026-07-31 10:45 UTCGHSA enrichment
  15. 2026-07-31 06:43 UTCVendor advisory
  16. 2026-07-31 06:43 UTCGHSA enrichment
  17. 2026-07-31 02:44 UTCVendor advisory
  18. 2026-07-31 02:43 UTCGHSA enrichment
  19. 2026-07-30 22:43 UTCGHSA enrichment
  20. 2026-07-30 18:44 UTCEG score recompute
  21. 2026-07-30 18:44 UTCVendor advisory
  22. 2026-07-30 18:44 UTCGHSA enrichment
  23. 2026-07-30 14:45 UTCVendor advisory
  24. 2026-07-30 14:45 UTCGHSA enrichment
  25. 2026-07-30 10:46 UTCEG score recompute
Show 75 more
  1. 2026-07-30 10:46 UTCVendor advisory
  2. 2026-07-30 10:46 UTCGHSA enrichment
  3. 2026-07-30 06:46 UTCVendor advisory
  4. 2026-07-30 06:46 UTCGHSA enrichment
  5. 2026-07-30 02:47 UTCEG score recompute
  6. 2026-07-30 02:47 UTCVendor advisory
  7. 2026-07-30 02:47 UTCGHSA enrichment
  8. 2026-07-30 01:30 UTCEPSS rescore
  9. 2026-07-29 22:47 UTCVendor advisory
  10. 2026-07-29 22:46 UTCGHSA enrichment
  11. 2026-07-29 19:27 UTCCISA KEV update
  12. 2026-07-29 18:46 UTCVendor advisory
  13. 2026-07-29 18:45 UTCGHSA enrichment
  14. 2026-07-29 14:45 UTCVendor advisory
  15. 2026-07-29 14:45 UTCGHSA enrichment
  16. 2026-07-29 10:45 UTCVendor advisory
  17. 2026-07-29 10:45 UTCGHSA enrichment
  18. 2026-07-29 06:46 UTCVendor advisory
  19. 2026-07-29 06:46 UTCGHSA enrichment
  20. 2026-07-29 02:48 UTCVendor advisory
  21. 2026-07-29 02:48 UTCGHSA enrichment
  22. 2026-07-28 22:48 UTCVendor advisory
  23. 2026-07-28 22:48 UTCGHSA enrichment
  24. 2026-07-28 18:47 UTCEG score recompute
  25. 2026-07-28 18:47 UTCVendor advisory
  26. 2026-07-28 18:47 UTCGHSA enrichment
  27. 2026-07-28 14:46 UTCVendor advisory
  28. 2026-07-28 14:45 UTCGHSA enrichment
  29. 2026-07-28 10:45 UTCVendor advisory
  30. 2026-07-28 10:45 UTCGHSA enrichment
  31. 2026-07-28 06:44 UTCVendor advisory
  32. 2026-07-28 06:44 UTCGHSA enrichment
  33. 2026-07-28 02:44 UTCVendor advisory
  34. 2026-07-28 02:44 UTCGHSA enrichment
  35. 2026-07-27 22:45 UTCVendor advisory
  36. 2026-07-27 22:45 UTCGHSA enrichment
  37. 2026-07-27 19:24 UTCCISA KEV update
  38. 2026-07-27 18:46 UTCVendor advisory
  39. 2026-07-27 18:46 UTCGHSA enrichment
  40. 2026-07-27 17:17 UTCCISA KEV update
  41. 2026-07-27 14:46 UTCEG score recompute
  42. 2026-07-27 14:46 UTCVendor advisory
  43. 2026-07-27 14:46 UTCGHSA enrichment
  44. 2026-07-27 14:13 UTCEPSS rescore
  45. 2026-07-27 09:35 UTCVendor advisory
  46. 2026-07-27 09:35 UTCGHSA enrichment
  47. 2026-07-27 05:36 UTCVendor advisory
  48. 2026-07-27 05:36 UTCGHSA enrichment
  49. 2026-07-27 01:37 UTCVendor advisory
  50. 2026-07-27 01:36 UTCGHSA enrichment
  51. 2026-07-26 21:37 UTCVendor advisory
  52. 2026-07-26 21:36 UTCGHSA enrichment
  53. 2026-07-26 17:37 UTCVendor advisory
  54. 2026-07-26 17:37 UTCGHSA enrichment
  55. 2026-07-26 13:37 UTCEG score recompute
  56. 2026-07-26 13:37 UTCVendor advisory
  57. 2026-07-26 13:37 UTCGHSA enrichment
  58. 2026-07-26 09:37 UTCVendor advisory
  59. 2026-07-26 09:37 UTCGHSA enrichment
  60. 2026-07-26 05:38 UTCVendor advisory
  61. 2026-07-26 05:38 UTCGHSA enrichment
  62. 2026-07-26 01:38 UTCEG score recompute
  63. 2026-07-26 01:38 UTCVendor advisory
  64. 2026-07-26 01:38 UTCGHSA enrichment
  65. 2026-07-25 14:17 UTCEPSS rescore
  66. 2026-07-25 14:17 UTCEPSS rescore
  67. 2026-07-24 14:17 UTCEPSS rescore
  68. 2026-07-23 14:18 UTCEPSS rescore
  69. 2026-07-23 14:18 UTCEPSS rescore
  70. 2026-07-23 03:06 UTCEG score recompute
  71. 2026-07-23 00:11 UTCEG score recompute
  72. 2026-07-23 00:11 UTCVendor advisory
  73. 2026-07-23 00:11 UTCGHSA enrichment
  74. 2026-07-22 20:11 UTCGHSA enrichment
  75. 2026-07-22 19:40 UTCCISA KEV update

Related CVEs(same vendor + same CWE)

Frequently asked(6)

What is CVE-2026-21533?
CVE-2026-21533 is a critical vulnerability published on February 10, 2026. Improper privilege management in Windows Remote Desktop allows an authorized attacker to elevate privileges locally.
When was CVE-2026-21533 disclosed?
CVE-2026-21533 was first published in the National Vulnerability Database on February 10, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-21533 actively exploited?
Yes. CISA added CVE-2026-21533 to the Known Exploited Vulnerabilities catalog on February 10, 2026, affecting Microsoft Windows. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2026-21533?
CVE-2026-21533 has a CVSS v3 base score of 7.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
Which products are affected by CVE-2026-21533?
CVE-2026-21533 affects Microsoft Windows. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2026-21533?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-21533, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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