CVE-2021-42287

CRITICALNVD 8.89.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2022-04-11), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 8.8 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: 77%CVSS: 8.8Exploit: cisa kev · ssvc active · kev ransomware · epss top5pct · epss high · public exploitExposed services: Not assessed

A fix is available — apply it.

Active Directory Domain Services Elevation of Privilege Vulnerability

CVSS v3
8.8
EG Score
9.0CRITICALhigh confidence
EG Risk
81
EG Risk 81/100CISA SSVC

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%
CISA SSVC: Track at low, Attend at medium and Act at high mission impact.
Action: A fix is available. Apply it within your standard update timelines at low, sooner than that at medium and as soon as possible at high mission impact.
EPSS PROB
77%
EPSS %ILE
99th
KEV
⚠ Exploited

CISA SSVCTrack at low, Attend at medium and Act at high mission impact.

A fix is available. Apply it within your standard update timelines at low, sooner than that at medium and as soon as possible at high mission impact.

Exploitation active (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

November 10, 2021

Last Modified

August 19, 2026

Advisory Details (2)

Auto-updated Jun 5, 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-2021-42287
microsoft Patch Available

Security Update Guide - Microsoft Security Response Center

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

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-42287

Vendor Advisories for CVE-2021-42287(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 100× in last 7d / 433× 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 1,745 total refreshes for this CVE.

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

Publicly available exploits

(6 references)

Working exploit code is in the public domain (6 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCDanielFEXKEX/CVE-Scanner
    First seen Apr 26, 2025

    CVE-2021-42287/CVE-2021-42278/OTHER Scanner & Exploiter.

    Open source ↗
  • GitHub PoCTryA9ain/noPac
    First seen Dec 22, 2022

    CVE-2021-42287/CVE-2021-42278 Exploiter

    Open source ↗
  • GitHub PoCXiaoliChan/Invoke-sAMSpoofing
    First seen Apr 1, 2022

    CVE-2021-42287/CVE-2021-42278 exploits in powershell

    Open source ↗
  • GitHub PoCknightswd/NoPacScan
    First seen Jan 7, 2022

    NoPacScan is a CVE-2021-42287/CVE-2021-42278 Scanner,it scan for more domain controllers than other script

    Open source ↗
  • GitHub PoCricardojba/Invoke-noPac
    First seen Dec 13, 2021

    .Net Assembly loader for the [CVE-2021-42287 - CVE-2021-42278] Scanner & Exploit noPac

    Open source ↗
  • GitHub PoCcube0x0/noPac
    First seen Dec 11, 2021

    CVE-2021-42287/CVE-2021-42278 Scanner & Exploiter.

    Open source ↗

Related CVEs(same CWE)

Frequently asked(6)

What is CVE-2021-42287?
CVE-2021-42287 is a critical vulnerability published on November 10, 2021. Active Directory Domain Services Elevation of Privilege Vulnerability
When was CVE-2021-42287 disclosed?
CVE-2021-42287 was first published on November 10, 2021, with the most recent update on August 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-42287 actively exploited?
Yes. CISA added CVE-2021-42287 to the Known Exploited Vulnerabilities catalog on April 11, 2022, affecting Microsoft Active Directory. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate attention. A fix is available. Apply it.
What is the CVSS score of CVE-2021-42287?
CVE-2021-42287 has a CVSS v3 base score of 8.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0 (CRITICAL).
Which products are affected by CVE-2021-42287?
CVE-2021-42287 affects Microsoft Active Directory.
How do I remediate CVE-2021-42287?
A fix for CVE-2021-42287 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2021-42287 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2021-42287

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