{"id":"CVE-2026-63346","title":"Refitter: C# source injection through OpenAPI header parameter names","summary":"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 wit…","severity":"high","cvss":8.6,"cvssVector":"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","cvssSource":"cna","cwe":["CWE-94","CWE-116"],"vendor":"christianhelle","product":"refitter","affected":["refitter < 2.1.2"],"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"total","timestamp":"2026-11-02T14:46:50.420778Z"},"exploitAvailable":true,"published":"2026-10-30","updated":"2026-11-02","sourceUpdated":"2026-11-02T14:47:20.841Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-63346","references":[{"url":"https://github.com/christianhelle/refitter/security/advisories/GHSA-58x9-vjvp-6mx8","label":"https://github.com/christianhelle/refitter/security/advisories/GHSA-58x9-vjvp-6mx8"},{"url":"https://github.com/christianhelle/refitter/pull/1178","label":"https://github.com/christianhelle/refitter/pull/1178"},{"url":"https://github.com/christianhelle/refitter/commit/63a19b03699a9c267d6fab5f758ec26484db83a1","label":"https://github.com/christianhelle/refitter/commit/63a19b03699a9c267d6fab5f758ec26484db83a1"},{"url":"https://github.com/christianhelle/refitter/releases/tag/2.1.2","label":"https://github.com/christianhelle/refitter/releases/tag/2.1.2"},{"url":"https://github.com/user-attachments/files/29395048/maintainer-report.txt","label":"https://github.com/user-attachments/files/29395048/maintainer-report.txt"},{"url":"https://github.com/user-attachments/files/29395050/make_spec.py","label":"https://github.com/user-attachments/files/29395050/make_spec.py"},{"url":"https://github.com/user-attachments/files/29395051/reproduce.sh","label":"https://github.com/user-attachments/files/29395051/reproduce.sh"}],"tags":["cve.org","exploit-available"],"epss":0.0035,"epssPercentile":0.28833,"ingestedAt":"2026-11-05T19:30:42.671Z","slug":"CVE-2026-63346","body":"## Overview\n\nRefitter 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.\n\n## Affected\n\n- `refitter < 2.1.2`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":59,"depthScoreParts":{"impact":47.3,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[]}