CVE-2026-63344
Refitter: C# source injection through OpenAPI content-type map keys
Refitter is a tool for generating a C# REST API client using the Refit library. Prior to 2.1.2, content-type keys in the content maps of `requestBody/responses` are emitted verbatim into a Refit `[Headers("Accept: <ct>", "Content-Type: <ct>")]` attribute string without escaping quotation marks. A crafted content-type key in an attacker-influenced OpenAPI description survives default validation without `--skip-validation`, breaks out of the attribute string and enclosing interface and namespace, and can introduce a top-level file class while leaving valid generated C#. A `[ModuleInitializer]` method in that class executes attacker code when the generated assembly is loaded at application startup, without requiring a call to the client. The behavior was verified with Refitter 2.0.0 and .NET 8. This issue is fixed in version 2.1.2.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| refitter christianhelle |
< 2.1.2 (affected) | CNA: GitHub_M |
RefitterRefitter
nuget |
<= 2.0.0 (affected, GitHub advisory range) | GitHub GHSA-p32v-8v8j-j534 |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 8.6 high |
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 | CNA: GitHub_M |
| 4.0 / 8.6 high |
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD: [email protected] |
Exploit evidence
- https://github.com/christianhelle/refitter/security/advisories/GHSA-p32v-8v8j-j534
exploit · ADP: CISA-ADP
References
- https://github.com/christianhelle/refitter/security/advisories/GHSA-p32v-8v8j-j534CNA: GitHub_M · x_refsource_CONFIRM
- https://github.com/christianhelle/refitter/pull/1178CNA: GitHub_M · x_refsource_MISC
- https://github.com/christianhelle/refitter/commit/ab4d8e439d6f0ee82ad49ee15323978d70fe5a67CNA: GitHub_M · x_refsource_MISC
- https://github.com/christianhelle/refitter/releases/tag/2.1.2CNA: GitHub_M · x_refsource_MISC
- https://github.com/user-attachments/files/29394848/reproduce.shCNA: GitHub_M · x_refsource_MISC
- https://github.com/user-attachments/files/29394851/maintainer-report.txtCNA: GitHub_M · x_refsource_MISC
- https://github.com/user-attachments/files/29394853/make_spec.pyCNA: GitHub_M · x_refsource_MISC
- https://github.com/christianhelle/refitter/security/advisories/GHSA-p32v-8v8j-j534ADP: CISA-ADP · exploit
- https://github.com/christianhelle/refitter/commit/ab4d8e439d6f0ee82ad49ee15323978d70fe5a67[email protected]
- https://github.com/christianhelle/refitter/pull/1178[email protected]
- https://github.com/christianhelle/refitter/releases/tag/2.1.2[email protected]
- https://github.com/christianhelle/refitter/security/advisories/GHSA-p32v-8v8j-j534[email protected]
- https://github.com/user-attachments/files/29394848/reproduce.sh[email protected]
- https://github.com/user-attachments/files/29394851/maintainer-report.txt[email protected]
- https://github.com/user-attachments/files/29394853/make_spec.py[email protected]
- https://github.com/christianhelle/refitter/security/advisories/GHSA-p32v-8v8j-j534GitHub Security Advisories · advisory
For agents and automation
Read public disclosures for free as Markdown or JSON. Compatible browsers also expose native WebMCP tools to search disclosures, read this page, and discover API access.
Use the ontology-linked Cyber API with x402 pay per request, or a Y2 Pro or Elite API key with the intel:cyber scope.
Endpoints and access details
https://api.y2.dev/api/v2/cyber/cveshttps://api.y2.dev/api/v2/cyber/cves/{cveId}
A workspace owner or admin can create a Pro or Elite API key. Send Authorization: Bearer <Y2_API_KEY> from your trusted agent runtime.
For x402, omit Authorization and read the HTTP 402 payment challenge before signing a retry. Public browser tools do not make payments.