ACTIVELY EXPLOITED

CVE-2021-26411: Microsoft Internet Explorer Memory Corruption Vulnerability

Facts
VendorMicrosoft
ProductInternet Explorer
Actively exploitedYes
Added to CISA KEV3 Nov 2021
CISA federal deadline17 Nov 2021
Ransomware useKnown
Weakness (CWE)CWE-416

Required action (CISA's text)

Apply updates per vendor instructions.

Description (NVD)

Microsoft Internet Explorer contains an unspecified vulnerability that allows for memory corruption.

SOURCES

Other Microsoft flaws

Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.