CVE-2026-21510
HIGH CISA KEV Actively ExploitedWindows 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
- 2/10/2026
- Patch Due Date
- 3/3/2026
- Required Action
- Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Technical Details
- CVSS v3 Vector
- 3.1
- Published
- 2/10/2026
- Last Modified
- 2/11/2026
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.