# CVE-2026-63184: Refitter unsafe $ref resolution in OpenAPI generation

Source: https://junglewise.ai/threats/cve-2026-63184-refitter-is-a-tool-for-generating-a-c-rest-api-client-using-the  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-30. Updated: 2026-10-30  
License: CC BY 4.0 with a link back

CVE-2026-63184 · Severity: high · CVSS 7.1 · Published 2026-10-30

Refitter is a code-generation tool that creates C# REST API clients from OpenAPI specifications. Before version 2.1.1, it could be tricked into fetching content from arbitrary remote URLs or local files when processing an attacker-controlled OpenAPI file, leaking sensitive data to an attacker or exposing files on the developer's machine. The vulnerability affects developers and CI/CD systems that process untrusted OpenAPI descriptions.

Technologies: [Christian Helle Refitter](https://junglewise.ai/threats/technologies/refitter). Vendors: [Christian Helle](https://junglewise.ai/threats/vendors/christian-helle).

## Quick answers

**Is CVE-2026-63184 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-63184 being exploited in the wild.

**How severe is CVE-2026-63184?** High severity, with a CVSS score of 7.1, published 30 October 2026.

**Which products and versions are affected?** Christian Helle Refitter before 2.1.1.

**Is there a fix for CVE-2026-63184?** Yes: fixed in 2.1.1. Until then: Pass the --allow-remote-refs flag only when processing trusted OpenAPI specifications; by default, remote references and out-of-directory local paths are now blocked. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-63184 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-63184?** Check whether you run Christian Helle Refitter at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 2.1.1

Pass the --allow-remote-refs flag only when processing trusted OpenAPI specifications; by default, remote references and out-of-directory local paths are now blocked.

## Technical details

The vulnerability exists in unsafe $ref resolution within NJsonSchema configuration used by the refitter dotnet tool. Remote http(s) $ref entries trigger server-side requests from the developer or CI host; absolute local file paths and directory-traversal sequences (../) allow reading files outside the input directory. The attack requires attacker-influenced or attacker-controlled OpenAPI input; no code execution is possible due to runtime constraints (base URL set at runtime, enum values use verbatim-string doubling, string defaults are escaped).

## Affected products

- Christian Helle Refitter before 2.1.1

## Timeline

- 2026-10-30: disclosed
- 2026-06-29: patched

## References

- [https://github.com/christianhelle/refitter/commit/6ad20a3803561225100b0a4bb6b12f947d23db7b](https://github.com/christianhelle/refitter/commit/6ad20a3803561225100b0a4bb6b12f947d23db7b)
- [https://github.com/christianhelle/refitter/pull/1173](https://github.com/christianhelle/refitter/pull/1173)

## Related threats

- [Refitter C# REST client generator code injection in header attribute](https://junglewise.ai/threats/cve-2026-63346-refitter-is-a-tool-for-generating-a-c-rest-api-client-using-the)
- [Refitter code injection in generated Refit headers](https://junglewise.ai/threats/cve-2026-63344-refitter-is-a-tool-for-generating-a-c-rest-api-client-using-the)