CVE-2026-21510

HIGH severity · CVSS 8.8 · CWE-693 · actively exploited (CISA KEV)

8.8CVSS HIGH ● exploited

🔴 Actively exploited in the wild (CISA Known Exploited Vulnerabilities). Added to KEV 2026-02-10. US federal agencies must patch by 2026-03-03.

Summary

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

Impact & exploitability

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionRequired

Confidentiality impactHigh

Integrity impactHigh

Availability impactHigh

Exploit probability (EPSS)5%

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

Affected products we track (1)

Windows Server 2025

Recommendation

This vulnerability is being actively exploited in the wild — patch affected products urgently. Open any affected product above for its exact safe version.

Additional information

NVD record
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21510Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21510