CVE-2021-26411 kev+ ransomware in the critical feed json
Internet Explorer Memory Corruption Vulnerability
published 2021-03-11 5 y ago modified 2026-10-01 38 d ago also EUVD-2021-13217
- cvss
- 8.8
- version 3.1, CNA
- cisa kev
- Exploited
- added 2021-11-03, used in ransomware
- epss
- 81.7%
- EPSS 81.7% chance of exploitation in 30 days, percentile 99.6%
- public exploits
- 0
- none known
Summary
Internet Explorer Memory Corruption Vulnerability
Patch / fix
cisa required action Apply updates per vendor instructions.
- Microsoft Internet Explorer 11 10.0.17134.2087
- Microsoft Internet Explorer 9 6.0.6003.21070
- Microsoft Microsoft Edge (EdgeHTML-based) 10.0.17134.2087
Timeline
- 0-day patched (Project Zero)
- Published
- Added to CISA KEV
- CISA patch deadline
- CISA SSVC: exploitation active
Known exploited
- Added
- 5 y ago
- Patch by
- 2021-11-17 (4 y ago)
- Ransomware
- Known to be used in ransomware campaigns
- Required action
- Apply updates per vendor instructions.
- Vendor, product
- Microsoft, Internet Explorer
- CISA name
- Microsoft Internet Explorer Memory Corruption Vulnerability
Zero-day
Detected in real attacks while still unknown to the vendor and the public, per Google Project Zero's 0day In-the-Wild tracker.
- Patched
- 2021-03-09
- Details
- project zero root cause analysis
CISA SSVC
- Exploitation
- Active, exploited in the wild
- Automatable
- no
- Technical impact
- partial
- Assessed
- 2 mo ago
Exploit prediction
81.67% chance of exploitation in the next 30 days, higher than 99.6% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:L/E:P/RL:O/RC:C |
| CNA | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:L |
| CNA | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 5.1 | AV:N/AC:H/Au:N/C:P/I:P/A:P |
Affected products
- Microsoft Internet Explorer 11
- Microsoft Internet Explorer 9
- Microsoft Microsoft Edge (EdgeHTML-based)
Classification
- Weakness
-
- CWE-416 Use After Free
References
-
msrc.microsoft.com
/update-guide/vulnerability/CVE-2021-26411
vendor-advisory, patch
-
portal.msrc.microsoft.com
/en-US/security-guidance/advisory/CVE-2021-26411
patch, vendor-advisory
-
cisa.gov
/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26411
government-resource, us-government-resource
Sources
- CVE List CVE-2021-26411
- NVD CVE-2021-26411
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