Unauthenticated service interruption via unreachable loop exit
Published May 12, 2026 · Updated May 12, 2026
Infinite-loop handling in ASP.NET Core in .NET 8 before 8.0.27, 9 before 9.0.16, and 10 before 10.0.8 allows remote attackers to interrupt service. Microsoft identifies a loop whose exit condition is unreachable but has not disclosed the affected code path, input structure, or exact condition. No authentication or user interaction is required; network input can consume processing indefinitely, with no reported data exposure or modification.
Summary
What happened
Infinite-loop handling in ASP.NET Core in .NET 8 before 8.0.27, 9 before 9.0.16, and 10 before 10.0.8 allows remote attackers to interrupt service. Microsoft identifies a loop whose exit condition is unreachable but has not disclosed the affected code path, input structure, or exact condition. No authentication or user interaction is required; network input can consume processing indefinitely, with no reported data exposure or modification.
The record
- CVE
- CVE-2026-42899
- Published
- May 12, 2026
- Updated
- May 12, 2026
- Vendor
- Microsoft
- Product
- .NET 9.0
- Classifications
- CWE-835, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 12, 2026CVE publishedPublication date reported by the CVE source.
- May 12, 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=9.0.0 <9.0.16
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
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Your stack
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