CVE-2025-21333

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 2025-01-14), 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: 10%CVSS: 7.8Exploit: cisa kev · ssvc active · epss top5pct · public exploitExposed: 0

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

Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability

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
10%
EPSS %ILE
95%
KEV
⚠ Exploited

Published

January 14, 2025

Last Modified

November 3, 2025

Advisory Details (5)

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-2025-21333
generic

CVE-2025-21333 - Elevated Privilege Exposure in Windows Hyper-V by Microsoft - Mitigation Script - vsociety

https://www.vicarius.io/vsociety/posts/cve-2025-21333-elevated-privilege-exposure-in-windows-hyper-v-by-microsoft-mitigation-script
generic

CVE-2025-21333 - Elevated Privilege Exposure in Windows Hyper-V by Microsoft - Detection Script - vsociety

https://www.vicarius.io/vsociety/posts/cve-2025-21333-elevated-privilege-exposure-in-windows-hyper-v-by-microsoft-detection-script
generic🟡 PoC Available

Microsoft Windows Server 2025 Hyper-V NT Kernel Integration VSP - Elevation of Privilege - Windows local Exploit

https://www.exploit-db.com/exploits/52436
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-2025-21333

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 62× in last 7d / 363× 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 733 total refreshes for this CVE.

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

Publicly available exploits

(3 references)

Working exploit code is in the public domain (2 GitHub PoCs) (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCnu1lptr0/CVE-2025-21333
    First seen May 5, 2026

    LPE due to integer truncation in vskrnlintvsp.sys

    Open source ↗
  • Exploit-DBEDB-52436
    First seen Sep 16, 2025

    Microsoft Windows Server 2025 Hyper-V NT Kernel Integration VSP - Elevation of Privilege

    Open source ↗
  • GitHub PoCMrAle98/CVE-2025-21333-POC
    First seen Feb 27, 2025

    POC exploit for CVE-2025-21333 heap-based buffer overflow. It leverages WNF state data and I/O ring IOP_MC_BUFFER_ENTRY

    Open source ↗

Related CVEs(same vendor + same CWE)

Frequently asked(6)

What is CVE-2025-21333?
CVE-2025-21333 is a critical vulnerability published on January 14, 2025. Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability
When was CVE-2025-21333 disclosed?
CVE-2025-21333 was first published in the National Vulnerability Database on January 14, 2025, with the most recent update on November 3, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-21333 actively exploited?
Yes. CISA added CVE-2025-21333 to the Known Exploited Vulnerabilities catalog on January 14, 2025, affecting Microsoft Windows. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2025-21333?
CVE-2025-21333 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-2025-21333?
CVE-2025-21333 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-2025-21333?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-21333, 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

Explore the affected products and dependency analysis for CVE-2025-21333

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