CVE-2026-32202
KEVmassSpoofing Flaw in Windows Shell (CVE-2026-32202) Actively Exploited
CISA: Microsoft Windows Protection Mechanism Failure Vulnerability
A protection mechanism in the Windows Shell fails (CWE-693), allowing an unauthorized attacker to perform spoofing against the shell over a network. Per the CVSS vector, the attack is network-based, requires no privileges or special conditions, but does require the targeted user to interact with attacker-supplied content. The impact is limited to confidentiality: an attacker can misrepresent information presented through the Windows Shell, gaining a spoofing foothold rather than code execution, privilege escalation, or persistence. Any organization running the affected Windows 10, Windows 11, or Windows Server builds is exposed, which effectively means most Windows estates. Microsoft has confirmed active exploitation, CISA added the flaw to its Known Exploited Vulnerabilities catalog on 2026-04-28, and a fix shipped in Microsoft's April 2026 Patch Tuesday release.
What to do: Apply Microsoft's April 2026 security updates to all affected Windows 10, Windows 11, and Windows Server hosts as a priority; the flaw is on CISA's KEV catalog, so U.S. federal agencies must patch within BOD 22-01 timelines or apply vendor-recommended mitigations. Until patched, note that exploitation requires user interaction with spoofed shell content, so user awareness about verifying shell-rendered information is a partial mitigations. No public PoC is known, but confirmed in-the-wild exploitation warrants prioritizing user-facing and internet-reachable systems for patching.
| microsoft Windows 10 | 1607 |
| microsoft Windows 10 | 1809 |
| microsoft Windows 10 | 21H2 |
| microsoft Windows 10 | 22H2 |
| microsoft Windows 11 | 23H2 |
| microsoft Windows 11 | 24H2 |
| microsoft Windows 11 | 25H2 |
| microsoft Windows 11 | 26H1 |
| microsoft Windows Server 2012 | 2012 |
| microsoft Windows Server 2016 | 2016 |
| microsoft Windows Server 2019 | 2019 |
| microsoft Windows Server 2022 | 2022 |
Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.
Protection mechanism failure in Windows Shell allows an unauthorized attacker to perform spoofing over a network.
- Affected
- Microsoft Windows
- 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.
- Due date
- Ransomware use
- Unknown
- Vendors
- microsoft
- Products
- windows 10 1607, windows 10 1809, windows 10 21h2, windows 10 22h2, windows 11 23h2, windows 11 24h2, windows 11 25h2, windows 11 26h1, windows server 2012, windows server 2016, windows server 2019, windows server 2022
- Weakness
- CWE-693
- Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N