Unauthenticated access via no-op authentication default
Published Aug 12, 2026 · Updated Aug 12, 2026
Authentication bypass in getkin kin-openapi before 0.144.0 allows remote attackers to reach protected handlers without credentials. ValidationHandler.Load() replaces a nil AuthenticationFunc with NoopAuthenticationFunc, whose nil return satisfies every OpenAPI security requirement instead of reaching the fail-closed error. The application must use ValidationHandler as enforcement middleware, declare security requirements, omit AuthenticationFunc, and lack separate upstream authentication; protected data and actions then become accessible.
Summary
What happened
Authentication bypass in getkin kin-openapi before 0.144.0 allows remote attackers to reach protected handlers without credentials. ValidationHandler.Load() replaces a nil AuthenticationFunc with NoopAuthenticationFunc, whose nil return satisfies every OpenAPI security requirement instead of reaching the fail-closed error. The application must use ValidationHandler as enforcement middleware, declare security requirements, omit AuthenticationFunc, and lack separate upstream authentication; protected data and actions then become accessible.
The record
- CVE
- CVE-2026-73501
- Published
- Aug 12, 2026
- Updated
- Aug 12, 2026
- Vendor
- getkin
- Product
- kin-openapi
- Classifications
- CWE-287, CAPEC-114, CAPEC-151, CAPEC-115, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 12, 2026CVE publishedPublication date reported by the CVE source.
- Aug 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=< 0.144.0
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
- GHSA-r277-6w6q-xmqw reproduction proof of conceptproof of concept · demonstrated
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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