CVE-2021-27085

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 2021-11-03), 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: 5%CVSS: 8.8Exploit: cisa kev · ssvc activeExposed: 0

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

Internet Explorer Remote Code Execution Vulnerability

CVSS v3
8.8
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
5%
EPSS %ILE
92%
KEV
⚠ Exploited

Published

March 11, 2021

Last Modified

August 19, 2026

Advisory Details (2)

Auto-updated Jun 2, 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-2021-27085
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-2021-27085

Vendor Advisories for CVE-2021-27085(1)

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

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 104× in last 7d / 389× 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 1,132 total refreshes for this CVE.

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

Frequently asked(6)

What is CVE-2021-27085?
CVE-2021-27085 is a critical vulnerability published on March 11, 2021. Internet Explorer Remote Code Execution Vulnerability
When was CVE-2021-27085 disclosed?
CVE-2021-27085 was first published in the National Vulnerability Database on March 11, 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-2021-27085 actively exploited?
Yes. CISA added CVE-2021-27085 to the Known Exploited Vulnerabilities catalog on November 3, 2021, affecting Microsoft Internet Explorer. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2021-27085?
CVE-2021-27085 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.
Which products are affected by CVE-2021-27085?
CVE-2021-27085 affects Microsoft Internet Explorer. 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-2021-27085?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-27085, 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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