{"id":"CVE-2026-63344","state":"PUBLISHED","title":"Refitter: C# source injection through OpenAPI content-type map keys","description":"Refitter is a tool for generating a C# REST API client using the Refit library. Prior to 2.1.2, content-type keys in the content maps of `requestBody/responses` are emitted verbatim into a Refit `[Headers(\"Accept: <ct>\", \"Content-Type: <ct>\")]` attribute string without escaping quotation marks. A crafted content-type key in an attacker-influenced OpenAPI description survives default validation without `--skip-validation`, breaks out of the attribute string and enclosing interface and namespace, and can introduce a top-level file class while leaving valid generated C#. A `[ModuleInitializer]` method in that class executes attacker code when the generated assembly is loaded at application startup, without requiring a call to the client. The behavior was verified with Refitter 2.0.0 and .NET 8. This issue is fixed in version 2.1.2.","publishedAt":"2026-10-30T22:15:27.846Z","updatedAt":"2026-10-30T22:15:27.846Z","severity":{"score":8.6,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["christianhelle refitter"],"affected":[{"vendor":"christianhelle","product":"refitter","versions":[{"version":"< 2.1.2","status":"affected"}]}],"references":["https://github.com/christianhelle/refitter/security/advisories/GHSA-p32v-8v8j-j534","https://github.com/christianhelle/refitter/pull/1178","https://github.com/christianhelle/refitter/commit/ab4d8e439d6f0ee82ad49ee15323978d70fe5a67","https://github.com/christianhelle/refitter/releases/tag/2.1.2","https://github.com/user-attachments/files/29394848/reproduce.sh","https://github.com/user-attachments/files/29394851/maintainer-report.txt","https://github.com/user-attachments/files/29394853/make_spec.py"],"weaknesses":["CWE-94","CWE-116"],"ingestedAt":"2026-10-30T22:26:06.415Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/63xxx/CVE-2026-63344.json","commit":"f02cde01d713f161fa6518ef321d5dace5470571","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-63344","state":"PUBLISHED","datePublished":"2026-10-30T22:15:27.846Z","dateUpdated":"2026-10-30T22:15:27.846Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-07-16T14:14:24.385Z"},"containers":{"cna":{"title":"Refitter: C# source injection through OpenAPI content-type map keys","descriptions":[{"lang":"en","value":"Refitter is a tool for generating a C# REST API client using the Refit library. Prior to 2.1.2, content-type keys in the content maps of `requestBody/responses` are emitted verbatim into a Refit `[Headers(\"Accept: <ct>\", \"Content-Type: <ct>\")]` attribute string without escaping quotation marks. A crafted content-type key in an attacker-influenced OpenAPI description survives default validation without `--skip-validation`, breaks out of the attribute string and enclosing interface and namespace, and can introduce a top-level file class while leaving valid generated C#. A `[ModuleInitializer]` method in that class executes attacker code when the generated assembly is loaded at application startup, without requiring a call to the client. The behavior was verified with Refitter 2.0.0 and .NET 8. This issue is fixed in version 2.1.2."}],"affected":[{"vendor":"christianhelle","product":"refitter","versions":[{"version":"< 2.1.2","status":"affected"}]}],"references":[{"url":"https://github.com/christianhelle/refitter/security/advisories/GHSA-p32v-8v8j-j534","name":"https://github.com/christianhelle/refitter/security/advisories/GHSA-p32v-8v8j-j534","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/christianhelle/refitter/pull/1178","name":"https://github.com/christianhelle/refitter/pull/1178","tags":["x_refsource_MISC"]},{"url":"https://github.com/christianhelle/refitter/commit/ab4d8e439d6f0ee82ad49ee15323978d70fe5a67","name":"https://github.com/christianhelle/refitter/commit/ab4d8e439d6f0ee82ad49ee15323978d70fe5a67","tags":["x_refsource_MISC"]},{"url":"https://github.com/christianhelle/refitter/releases/tag/2.1.2","name":"https://github.com/christianhelle/refitter/releases/tag/2.1.2","tags":["x_refsource_MISC"]},{"url":"https://github.com/user-attachments/files/29394848/reproduce.sh","name":"https://github.com/user-attachments/files/29394848/reproduce.sh","tags":["x_refsource_MISC"]},{"url":"https://github.com/user-attachments/files/29394851/maintainer-report.txt","name":"https://github.com/user-attachments/files/29394851/maintainer-report.txt","tags":["x_refsource_MISC"]},{"url":"https://github.com/user-attachments/files/29394853/make_spec.py","name":"https://github.com/user-attachments/files/29394853/make_spec.py","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"ACTIVE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.6,"baseSeverity":"HIGH","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-94","lang":"en","description":"CWE-94: Improper Control of Generation of Code ('Code Injection')","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-116","lang":"en","description":"CWE-116: Improper Encoding or Escaping of Output","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-30T22:15:27.846Z"},"source":{"advisory":"GHSA-p32v-8v8j-j534","discovery":"UNKNOWN"}}}}}