CVE-2026-63184 Details
Description
Refitter is a tool for generating a C# REST API client using the Refit library. Prior to 2.1.1, the `refitter` dotnet tool invokes `NJsonSchema` with unsafe defaults for `$ref` resolution when generating Refit interfaces and contracts from attacker-controlled or attacker-influenced OpenAPI descriptions. Remote `http(s)` references cause requests from the developer or CI host and inline untrusted remote schema content into generated output. Absolute local file paths and relative `../` traversal outside the input directory also resolve and inline local content, permitting arbitrary local-file disclosure. The demonstrated chain stops at server-side request forgery, remote file inclusion, and local file inclusion, not code execution: Refit sets the base URL at runtime, enum values use verbatim-string doubling, and string defaults are escaped. This issue is fixed in version 2.1.1.
A vulnerability in the Refitter tool for generating C# REST API clients exists in versions prior to 2.1.1. The issue arises because the tool's dotnet command-line interface allows remote and local file references to be resolved and inlined into the generated code. This behavior can be exploited by manipulating the OpenAPI specification that Refitter processes. Remote references can lead to server-side request forgery (SSRF) by causing the developer's or CI host's environment to fetch external resources. Additionally, local file references can be used to read arbitrary files from the file system, including those outside the specified input directory, thereby disclosing sensitive information. While the vulnerability does not allow for code execution, it introduces significant risks by enabling unauthorized file access and injection of untrusted content into the application.
Users can update to Refitter version 2.1.1, which addresses the vulnerability by confining `$ref` resolution to the input directory and blocking remote references by default.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Oct 30, 2026CISA-ADP
Assessed Nov 2, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-829 | Inclusion of Functionality from Untrusted Control Sphere | [email protected] |
| CWE-918 | Server-Side Request Forgery (SSRF) | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| Refitter | <= 2.0.0 (semver) |
CPE
Remediation
| |
Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Nov 2, 2026 | CVE Modified | CISA-ADP |
| Oct 30, 2026 | New CVE Received | [email protected] |