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HIGH CISA KEV Actively Exploited

CVE-2026-21510

Windows Shell Security Feature Bypass Vulnerability

CVSS v3

8.8

HIGH

EPSS Score

4.0 %

exploit probability

CISA KEV

Yes

known exploited

Exploitation

active

SSVC status

Description

Protection mechanism failure in Windows Shell allows an unauthorized attacker to bypass a security feature over a network.

CISA Known Exploited Vulnerability

Date Added
2026-02-10
Patch Due Date
2026-03-03
Ransomware Use
Unknown

Technical details

CVSS v3 Vector
3.1
Published
2026-02-10
Last Modified
2026-02-11

Frequently asked questions

What is CVE-2026-21510?

Protection mechanism failure in Windows Shell allows an unauthorized attacker to bypass a security feature over a network.

Is CVE-2026-21510 actively exploited?

Yes. CVE-2026-21510 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 3/3/2026.

What is the CVSS score for CVE-2026-21510?

CVE-2026-21510 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string 3.1.

Is CVE-2026-21510 affecting your environment?

Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.

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