CASCACascade Atlas

Evidence dossier

CVE-2021-26411

Internet Explorer Memory Corruption Vulnerability

70.7–95.0Priority evidence range
As known Jul 19, 2026, 5:00 AM UTCgen-56ccdaf9

Normalized restatement

Internet Explorer Memory Corruption Vulnerability

State
PUBLISHED
Published
Mar 11, 2021
Updated
Oct 21, 2025
Evidence coverage
72%
CISA KEVCatalog member

Apply updates per vendor instructions.

FIRST EPSS80.67%

2026-07-18 · v2026.06.15 · percentile 99.6%

Source stateConflict visible

Distinct CVSS assessments remain side by side; none are averaged.

Source comparison

Who said what

CISA-ADPindependent enrichment
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CISA ADP Vulnrichment

CVEderivative copy
container

CVE Program Container

microsoftoriginal assertion
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Internet Explorer Memory Corruption Vulnerability

CISA KEVoriginal assertion
observed_exploitation

Microsoft Internet Explorer Memory Corruption Vulnerability

FIRST EPSSoriginal assertion
model_probability

Probability 0.806670000000; percentile 0.995830000000

Applicability

Cited product scope

Trace impact →
MicrosoftInternet Explorer 11
[{"status": "affected", "version": "1.0.0", "lessThan": "publication", "versionType": "custom"}]unknown
MicrosoftInternet Explorer 9
[{"status": "affected", "version": "1.0.0", "lessThan": "publication", "versionType": "custom"}]unknown
MicrosoftMicrosoft Edge (EdgeHTML-based)
[{"status": "affected", "version": "1.0..0", "lessThan": "publication", "versionType": "custom"}]unknown
Unknown vendorUnknown product
cpe:2.3:a:microsoft:edge:-:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:a:microsoft:internet_explorer:11:-:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:a:microsoft:internet_explorer:9:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_10_1507:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_10_1507:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_10_1607:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_10_1607:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_10_1803:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_10_1803:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_10_1809:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_10_1809:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_10_1909:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_10_1909:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_10_2004:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_10_2004:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_10_20h2:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_10_20h2:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_7:-:sp1:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_rt_8.1:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_server_2016:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_server_2016:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_server_2019:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:microsoft:windows_server_2019:-:*:*:*:*:*:*:*constrained

Assessments

CVSS by origin

5.1
nvd@nist.govCVSS 2.0 · role PrimaryAV:N/AC:H/Au:N/C:P/I:P/A:P
8.8
nvd@nist.govCVSS 3.1 · role SecondaryCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
8.8
secure@microsoft.comCVSS 3.1 · role SecondaryCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:L
8.8
microsoftCVSS 3.1 · role unknownCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:L/E:P/RL:O/RC:C

Limitations and unknowns

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; unresolved scope remains unknown.
  • NVD-carried upstream facts remain derivative and are not independent corroboration.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Factor D is unknown in Public Core because no accepted canonical mapping-obligation ledger is present.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.