Overview
Microsoft Windows Shell contains a protection mechanism failure vulnerability that could allow an unauthorized attacker to bypass a security feature over a network.
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21510 ; https://nvd.nist.gov/vuln/detail/CVE-2026-21510
Key Details
| Property | Value |
|---|---|
| CVE ID | CVE-2026-21510 |
| Vendor / Product | Microsoft — Windows |
| NVD Published | 2026-02-10 |
| NVD Last Modified | 2026-02-11 |
| CVSS 3.1 Score | 8.8 |
| CVSS 3.1 Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| Severity | HIGH |
| CWE | CWE-693 |
| CISA KEV Added | 2026-02-10 |
| CISA KEV Deadline | 2026-03-03 |
| Known Ransomware Use | No |
CVSS 3.1 Breakdown
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Required Action
CISA BOD 22-01 Deadline: 2026-03-03.
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Timeline
| Date | Event |
|---|---|
| 2026-02-10 | Added to CISA Known Exploited Vulnerabilities catalog |
| 2026-03-03 | CISA BOD 22-01 remediation deadline |
References
| Resource | Type |
|---|---|
| NVD — CVE-2026-21510 | Vulnerability Database |
| CISA KEV Catalog Entry | US Government |