Refitter is a tool for generating a C# REST API client using the Refit library. Prior to 2.1.2, OpenAPI `paths`-object keys are emitted verbatim into Refit route attributes such as `[Get("<path>")]` without escaping quotation marks or restricting characters. An attacker-influenced single-line, slash-prefixed path survives default validation without `--skip-validation` and can close the attribute string, interface, and namespace while introducing a top-level file class and reopening the generated structure to keep valid C#. A `[ModuleInitializer]` method executes attacker code when an application compiles and loads the generated assembly at startup, even without calling the generated client. The enum and default value sinks are escaped and are not the vulnerable path-emission sink. The behavior was verified on Refitter 2.0.0 with .NET 8. This issue is fixed in version 2.1.2.
History

Tue, 03 Nov 2026 17:00:00 +0000

Type Values Removed Values Added
First Time appeared Christianhelle
Christianhelle refitter
Vendors & Products Christianhelle
Christianhelle refitter

Mon, 02 Nov 2026 19:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Fri, 30 Oct 2026 22:15:00 +0000

Type Values Removed Values Added
Description Refitter is a tool for generating a C# REST API client using the Refit library. Prior to 2.1.2, OpenAPI `paths`-object keys are emitted verbatim into Refit route attributes such as `[Get("<path>")]` without escaping quotation marks or restricting characters. An attacker-influenced single-line, slash-prefixed path survives default validation without `--skip-validation` and can close the attribute string, interface, and namespace while introducing a top-level file class and reopening the generated structure to keep valid C#. A `[ModuleInitializer]` method executes attacker code when an application compiles and loads the generated assembly at startup, even without calling the generated client. The enum and default value sinks are escaped and are not the vulnerable path-emission sink. The behavior was verified on Refitter 2.0.0 with .NET 8. This issue is fixed in version 2.1.2.
Title Refitter: C# source injection through OpenAPI path keys
Weaknesses CWE-1116
CWE-94
References
Metrics cvssV4_0

{'score': 8.6, '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'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-10-30T22:13:53.498Z

Updated: 2026-11-02T17:58:04.730Z

Reserved: 2026-07-16T14:14:24.385Z

Link: CVE-2026-63345

cve-icon Vulnrichment

Updated: 2026-11-02T17:09:23.147Z

cve-icon NVD

Status : Deferred

Published: 2026-10-30T23:17:13.987

Modified: 2026-11-02T19:35:33.347

Link: CVE-2026-63345

cve-icon Redhat

No data.