---
id: "CVE-2026-63184"
kind: "vulnerability"
aliases: ["CVE-2026-63184"]
title: "Refitter: crafted OpenAPI files cause SSRF and local file disclosure"
severity: "high"
cvss: 7.1
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["ci", "dotnet", "openapi", "package", "refit"]
not_affected_if: ["own-reviewed-specs-only", "version-2.1.1-or-later"]
published_at: "2026-10-30T22:16:58+00:00"
first_seen_at: "2026-10-30T22:25:57+00:00"
updated_at: "2026-10-30T22:27:11+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63184", "first_seen_at": "2026-10-30T22:25:57+00:00"}]
---

# Refitter: crafted OpenAPI files cause SSRF and local file disclosure

Refitter is a .NET tool that generates C# Refit API clients from OpenAPI files. Before 2.1.1 it resolves attacker-influenced $ref links, so a crafted spec can make the generating machine fetch remote URLs or read local files and copy their contents into the generated code.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed version of the `refitter` dotnet tool, for example with `dotnet tool list`
- Look for `refitter` in CI pipelines and developer scripts that generate clients from OpenAPI descriptions you do not fully control
- Review whether generation runs on OpenAPI files from third parties or unreviewed sources

## Fix

- `refitter` version `2.1.1` or later, per the source

## Timeline

- 2026-10-30T22:25:57+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-63184

## From the sources

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.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_