Vulnerability record

CVE-2021-26411

Microsoft Internet Explorer Memory Corruption Vulnerability

Severity: HighExploitation: Exploitation confirmedCISA KEV Used by ransomware
What should I do?

This vulnerability is in the CISA Known Exploited Vulnerabilities catalog: attackers are using it. If you run Internet Explorer, fix it now.

CISA required action: Apply updates per vendor instructions.

US federal civilian agencies must remediate by Nov 17, 2021.

Patch status

Official fix available since

Apply the vendor's update to every affected system. Check the fixed-in versions below where known.

Basis: NVD patch reference

Description

Internet Explorer Memory Corruption Vulnerability

Source: NIST National Vulnerability Database. Official vulnerability data, reproduced as published.

Affected products

Products affected by this vulnerability, with versions and the source of each entry
ProductVendorAffected versionsSource
Internet ExplorerMicrosoft11; 9KEV
Microsoft EdgeMicrosoftall versionsNVD

Sources: KEV = CISA Known Exploited Vulnerabilities catalog; NVD = NIST National Vulnerability Database.

Intelligence timeline

Developments from the last 30 days, newest first.

  1. CVSS scoredUpdateKEV

    CVE-2021-26411 scored CVSS 8.8: Microsoft Internet Explorer, Microsoft Internet Explorer Memory Corruption Vulnerability

    CISA lists this as exploited in the wild and known to be used in ransomware campaigns. Unpatched Internet Explorer systems are exposed to active attacks now.

    Basis: NIST National Vulnerability Database

  2. Patch releasedUpdateKEV

    Patch released for CVE-2021-26411: Microsoft Internet Explorer, Microsoft Internet Explorer Memory Corruption Vulnerability

    An official fix is now available for Microsoft Internet Explorer. This vulnerability is being exploited, so apply it promptly.

    Basis: NVD patch reference

1 earlier event is available with a subscription. See plans.

Coverage

We have not published a story about this vulnerability yet.

References

  • nvd.nist.gov https://nvd.nist.gov/vuln/detail/CVE-2021-26411
  • msrc.microsoft.com https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-26411
  • portal.msrc.microsoft.com https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26411
  • cisa.gov https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26411