CVE-2026-63184
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 `$ref` resolution when generating Refit interfaces and contracts from attacker-controlled or attacker-influenced OpenAPI descriptions. Remote `http(s)` references cause requests from the developer or CI host and inline untrusted remote schema content into generated output. Absolute local file paths and relative `../` traversal outside the input directory also resolve and inline local content, permitting arbitrary local-file disclosure. The demonstrated chain stops at server-side request forgery, remote file inclusion, and local file inclusion, not code execution: Refit sets the base URL at runtime, enum values use verbatim-string doubling, and string defaults are escaped. This issue is fixed in version 2.1.1.
Executive briefing
The source record describes: Refitter is a tool for generating a C# REST API client using the Refit library. Prior to 2.1.1, the `refitter` dotnet tool invokes `NJsonSchema` with unsafe defaults for `$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. The practical risk depends on whether an affected product/version is present, reachable and configured in an exploitable way. Review the affected-product evidence and linked vendor advisories before assigning exposure status.
Evidence confidence: Limited Evidence-derived, not an exploitability verdict
Severity & attack characteristics
CVSS vector:CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N
Technical explanation & impact
The technical mechanism is not expanded beyond the source description unless a referenced advisory supplies additional evidence. Read the linked vendor/CERT advisories for root-cause detail.
Potential impact must be interpreted from the published CVSS impact metrics and the affected component. A CVSS impact score is not proof that a particular asset is exploitable.
Weakness classification
CWE-829CWE-918Affected products and versions
NVD has not supplied machine-readable vulnerable CPE product/version entries for this CVE. This is an information gap, not proof that no products are affected. Check the vendor advisory references below.
Remediation & validation
- Identify exposure by comparing the affected product and version ranges with your asset inventory, SBOM and externally exposed services.
- Review the linked vendor security advisory or patch notes. Upgrade to a vendor-confirmed fixed release; do not infer a fixed version from the CVE description.
- Until patched, consider restricting network access or disabling the affected feature where operationally safe. These are temporary controls, not a substitute for a vendor fix.
- Validate the remediation with a version check and vulnerability rescan, then retain change evidence.
No fixed version is displayed unless it is explicitly established by a vendor advisory. Follow the vendor's release notes for exact product and branch applicability.
Vendor advisories, patches & exploit references
- https://github.com/christianhelle/refitter/commit/6ad20a3803561225100b0a4bb6b12f947d23db7b VENDOR security-advisories@github.com
- https://github.com/christianhelle/refitter/pull/1173 VENDOR security-advisories@github.com
- https://github.com/christianhelle/refitter/releases/tag/2.1.1 VENDOR security-advisories@github.com
- https://github.com/christianhelle/refitter/security/advisories/GHSA-x6w4-f264-3vvr VENDOR security-advisories@github.com
- https://github.com/user-attachments/files/29395269/reproduce.sh VENDOR security-advisories@github.com
- https://github.com/user-attachments/files/29395271/maintainer-report.txt VENDOR security-advisories@github.com
- https://github.com/user-attachments/files/29395272/advisory.md ADVISORY security-advisories@github.com
- https://github.com/user-attachments/files/29395283/reproduce.sh VENDOR security-advisories@github.com
- https://github.com/user-attachments/files/29395284/maintainer-report.txt VENDOR security-advisories@github.com
- https://github.com/user-attachments/files/29395285/advisory.md ADVISORY security-advisories@github.com
- https://github.com/user-attachments/files/29395286/listener.py VENDOR security-advisories@github.com
- https://github.com/user-attachments/files/29395288/make_spec.py VENDOR security-advisories@github.com
- https://github.com/christianhelle/refitter/security/advisories/GHSA-x6w4-f264-3vvr VENDOR 134c704f-9b21-4f2e-91b3-4a467353bcc0
Information gaps & confidence notes
These gaps indicate missing source data. CVE Watch does not fill them with guessed product, exploit or patch details.
- NVD does not currently provide machine-readable vulnerable CPE product/version entries for this record.
Last enrichment: 2026-11-04T04:32:04+00:00 · Source last modified: 2026-11-02T19:35:33.347