Refitter: C# source injection through OpenAPI header parameter names
Impact
Refitter is a tool for generating a C REST API client using the Refit library. Prior to 2.1.2, the header parameter name in parameters[].name with in: header is emitted verbatim into a Refit [Header("")] attribute string without escaping quotation marks. An attacker-influenced OpenAPI description can pass default validation without --skip-validation and break out from the parameter-list position by closing the parameter and method syntax, attribute, interface, and namespace. The generated file can remain valid C while containing a top-level file class with a [ModuleInitializer] method,…
Source excerpt · GitHub_MAffected packages
Affected products
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christianhelle · GitHub_M
refitter
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christianhelle · GitHub_M
refitter
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affected
< 2.1.2
Other versions: unknown
Original source description
Refitter is a tool for generating a C# REST API client using the Refit library. Prior to 2.1.2, the header parameter name in parameters[].name with in: header is emitted verbatim into a Refit [Header("<name>")] attribute string without escaping quotation marks. An attacker-influenced OpenAPI description can pass default validation without --skip-validation and break out from the parameter-list position by closing the parameter and method syntax, attribute, interface, and namespace. The generated file can remain valid C# while containing a top-level file class with a [ModuleInitializer] method, which executes attacker code when the compiled assembly is loaded at application startup, even if the client is never called. Query AliasAs and enum/default value sinks are escaped; this flaw is in header-name attribute-string emission. The behavior was verified with Refitter 2.0.0 and .NET 8. This issue is fixed in version 2.1.2.
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Original records
CVE-2026-63346View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.
cve.new JSON →Underlying weaknesses
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