CVE-2021-31199

CRITICALNVD 5.29.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 5.2 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: 3%CVSS: 5.2Exploit: cisa kev · ssvc activeExposed: 0

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

Microsoft Enhanced Cryptographic Provider Elevation of Privilege Vulnerability

CVSS v3
5.2
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
3%
EPSS %ILE
87%
KEV
⚠ Exploited

Published

June 8, 2021

Last Modified

October 30, 2025

Advisory Details (2)

Auto-updated Jun 14, 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-2021-31199
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-2021-31199

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 97× in last 7d / 401× 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 1,470 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(6)

What is CVE-2021-31199?
CVE-2021-31199 is a critical vulnerability published on June 8, 2021. Microsoft Enhanced Cryptographic Provider Elevation of Privilege Vulnerability
When was CVE-2021-31199 disclosed?
CVE-2021-31199 was first published in the National Vulnerability Database on June 8, 2021, with the most recent update on October 30, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-31199 actively exploited?
Yes. CISA added CVE-2021-31199 to the Known Exploited Vulnerabilities catalog on November 3, 2021, affecting Microsoft Enhanced Cryptographic Provider. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2021-31199?
CVE-2021-31199 has a CVSS v3 base score of 5.2 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
Which products are affected by CVE-2021-31199?
CVE-2021-31199 affects Microsoft Enhanced Cryptographic Provider. 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-2021-31199?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-31199, 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-2021-31199

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