Ghostwire

CVE-2026-63344: 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...

HIGH CVSS 0.0 EPSS 0.35%

Published: October 30, 2026 | Last Modified: October 30, 2026

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: ", "Content-Type: ")]` 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.

Ghostwire Analysis — What This Means Practically

Exploitation Probability (EPSS): Low — 0.35% (29th percentile)

Low exploitation probability based on current threat landscape data. Standard patching timeline is appropriate.

This analysis is generated by Ghostwire from NVD, CISA KEV, EPSS, and open-source intelligence data. Verify findings through primary sources before acting.

Security Coverage (1 articles)

References