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Known exploited vulnerability

CVE-2021-26411

highCVSS 3.1 8.8In CISA KEVRansomwareEPSS 82%Published · Microsoft

The short answer

CVE-2021-26411 affects Microsoft Internet Explorer 11 and is rated high (CVSS 8.8). CISA added it to the Known Exploited Vulnerabilities catalog on 2021-11-03: attackers are using it, so patch it first. The vendor has linked a patch.

What it is

Internet Explorer Memory Corruption Vulnerability

Weakness: CWE-416.

Severity

8.8 high

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:L

Exploited (CISA KEV)

Yes, since Nov 3, 2021

Federal due date Nov 17, 2021

EPSS, next 30 days

82%

Higher than 100% of scored CVEs

How it can be exploited

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Changed
Confidentiality impact
Low
Integrity impact
High
Availability impact
Low

What CISA says to do

Apply updates per vendor instructions.

Affected products

Internet Explorer 11, Internet Explorer 9, Microsoft Edge (EdgeHTML-based). NVD's record lists the exact affected versions.

References

Questions

Is CVE-2021-26411 being exploited?

Yes. CISA added CVE-2021-26411 to its Known Exploited Vulnerabilities catalog on 2021-11-03, with a federal remediation due date of 2021-11-17. CISA lists it as used in ransomware campaigns.

How do I fix CVE-2021-26411?

CISA's required action: Apply updates per vendor instructions.

From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.

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