Unauthenticated service interruption via improper input validation
Published Apr 14, 2026 · Updated Apr 14, 2026
Improper input validation in Microsoft .NET Framework allows remote attackers to interrupt service over a network. Microsoft has not disclosed the affected component, the untrusted input, or the validation operation that handles it incorrectly. No authentication or user interaction is required, but Microsoft has not stated whether exploitation causes a crash, hang, or another interruption mode.
Summary
What happened
Improper input validation in Microsoft .NET Framework allows remote attackers to interrupt service over a network. Microsoft has not disclosed the affected component, the untrusted input, or the validation operation that handles it incorrectly. No authentication or user interaction is required, but Microsoft has not stated whether exploitation causes a crash, hang, or another interruption mode.
The record
- CVE
- CVE-2026-23666
- Published
- Apr 14, 2026
- Updated
- Apr 14, 2026
- Vendor
- Microsoft
- Product
- Microsoft .NET Framework 3.5 and 4.8
- Classifications
- CWE-755, CWE-366, T1499
- 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
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=4.8.0 <2.0.50727.9068 & 3.0.30729.9065 & 4.8.4801.0
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.
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Technologies
Your stack
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Your stack
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