Microsoft Internet Explorer Memory Corruption Vulnerability
Microsoft Internet Explorer contains an unspecified vulnerability that allows for memory corruption.
- Vendor
- Microsoft
- Product
- Internet Explorer
- CVSS
- 8.8
- EPSS (exploit probability)
- 81.7%
- Status
- kevransomware use
- CISA patch-by (BOD 22-01)
- Added to KEV
Is CVE-2021-26411 being exploited?
Yes. CISA added CVE-2021-26411 to its Known Exploited Vulnerabilities catalog on . CISA only lists a CVE when it has reliable evidence of exploitation in the wild. CISA marks it as known to be used in ransomware campaigns.
FIRST's EPSS model puts the probability of exploitation activity in the next 30 days at 81.7% (scored October 20, 2026).
- CISA KEV[ LISTED ]
- ENISA EUVD (exploited)[ — ]
- CIRCL KEV[ — ]
Catalog snapshot 2026-11-13. Full cross-catalog view: /kev-comparison
CVE-2021-26411 timeline
Every event links to its source. Catalog dates are each catalog's own; day offsets count from NVD publication. Data: JSON
What to do
CISA required actionApply updates per vendor instructions.
US federal civilian agencies must remediate by (14 days after listing) under BOD 22-01. Everyone else: that deadline is a sensible upper bound, not a target. Vendor guidance and the NVD record are linked under Source above.
Other Microsoft Internet Explorer CVEs we track
| CVE / Vulnerability | Severity | CVSS | EPSS | Added to KEV |
|---|---|---|---|---|
| CVE-2010-0806 Microsoft Internet Explorer Use-After-Free Vulnerability | [ HIGH ] | 8.8 | 82.1% | |
| CVE-2010-0249 Microsoft Internet Explorer Use-After-Free Vulnerability | [ HIGH ] | 8.8 | 91.9% | |
| CVE-2010-3962 Microsoft Internet Explorer Uninitialized Memory Corruption Vulnerability | [ HIGH ] | 8.1 | 96.8% | |
| CVE-2013-3893 Microsoft Internet Explorer Resource Management Errors Vulnerability | [ HIGH ] | 8.8 | 87.6% | |
| CVE-2012-4792 Microsoft Internet Explorer Use-After-Free Vulnerability | [ HIGH ] | 8.8 | 78.8% | |
| CVE-2013-3163 Microsoft Internet Explorer Memory Corruption Vulnerability | [ HIGH ] | 8.8 | 70.7% | |
| CVE-2012-4969 Microsoft Internet Explorer Use-After-Free Vulnerability | [ HIGH ] | 8.1 | 80.3% | |
| CVE-2015-2425 Microsoft Internet Explorer Memory Corruption Vulnerability | [ HIGH ] | 8.8 | 44.7% |