Authenticated privilege escalation via improper Negotiate validation
Published Jul 14, 2026 · Updated Jul 14, 2026
Incorrect authentication in ASP.NET Core Negotiate allows remote authenticated users to elevate privileges over a network. Microsoft identifies improper validation in the Negotiate authentication handler but has not disclosed the rejected input or incorrect validation operation. Only applications configured for Negotiate authentication with LDAP role retrieval are exposed; higher privileges grant control over protected application resources.
Summary
What happened
Incorrect authentication in ASP.NET Core Negotiate allows remote authenticated users to elevate privileges over a network. Microsoft identifies improper validation in the Negotiate authentication handler but has not disclosed the rejected input or incorrect validation operation. Only applications configured for Negotiate authentication with LDAP role retrieval are exposed; higher privileges grant control over protected application resources.
The record
- CVE
- CVE-2026-47300
- Published
- Jul 14, 2026
- Updated
- Jul 14, 2026
- Vendor
- Microsoft
- Product
- .NET 9.0
- Classifications
- CWE-303, CAPEC-90, T1078
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 14, 2026CVE publishedPublication date reported by the CVE source.
- Jul 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=9.0.0 <9.0.18
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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