Unauthenticated security bypass via improper input validation
Published Apr 14, 2026 · Updated Apr 14, 2026
Improper input validation in Microsoft Windows Hello on affected Windows Server releases allows remote attackers to bypass a security feature. Microsoft has not disclosed the affected Windows Hello component, accepted input, validation error, or network request that triggers the bypass. No credentials or user interaction are required, although exploitation requires complex network conditions and permits access to and alteration of protected information.
Summary
What happened
Improper input validation in Microsoft Windows Hello on affected Windows Server releases allows remote attackers to bypass a security feature. Microsoft has not disclosed the affected Windows Hello component, accepted input, validation error, or network request that triggers the bypass. No credentials or user interaction are required, although exploitation requires complex network conditions and permits access to and alteration of protected information.
The record
- CVE
- CVE-2026-27928
- Published
- Apr 14, 2026
- Updated
- Apr 14, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2019
- Classifications
- CWE-20
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 14, 2026CVE publishedPublication date reported by the CVE source.
- Apr 14, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.17763.0 <10.0.17763.8644
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo