CISA KEV · Known exploitedHigh

CVE-2021-26411

Microsoft Internet Explorer

CVE-2021-26411 affects Microsoft Internet Explorer. Review the CVSS score, exploitation signals, affected versions, remediation status, and linked source material before making a change.

CVSS
8.8
EPSS
80.7%
99.6% percentile
CISA KEV
Listed
Published
2021.03.12
PRIORITY ASSESSMENT

Immediate review

CISA has listed this vulnerability in the Known Exploited Vulnerabilities catalog.

Known exploitationConfirmed by CISA KEV
Exploit probability80.7%
Technical severityCVSS 8.8

Vulnerability overview

CVE-2021-26411 affects Microsoft Internet Explorer. Review the CVSS score, exploitation signals, affected versions, remediation status, and linked source material before making a change.

Affected product and versions

Product
Microsoft Internet Explorer
Affected versions
1.0.0, 1.0..0, 11, 9
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
CISA required action

Apply updates per vendor instructions.

Due date: 2021.11.17
  1. 1
    Identify

    Confirm that Microsoft Internet Explorer and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CWE
CWE-416
KEV added
2021.11.03
Ransomware use
확인됨
CVE-2021-26411 — Microsoft Internet Explorer | SECUFOCUS NOW