Vulnerability 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.
Related Weaknesses (CWE)
References
- https://github.com/christianhelle/refitter/commit/ab4d8e439d6f0ee82ad49ee1532397
- https://github.com/christianhelle/refitter/pull/1178
- https://github.com/christianhelle/refitter/releases/tag/2.1.2
- https://github.com/christianhelle/refitter/security/advisories/GHSA-p32v-8v8j-j5
- 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
FAQ
What is CVE-2026-63344?
CVE-2026-63344 is a documented vulnerability. 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 `[Hea...
How severe is CVE-2026-63344?
CVSS scoring is not yet available for CVE-2026-63344. Check NVD for updates.
Is there a patch for CVE-2026-63344?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.