Refitter: C# source injection through OpenAPI path keys
Summary
| CVE | CVE-2026-63345 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-30 23:17:13 UTC |
| Updated | 2026-10-30 23:17:13 UTC |
| Description | Refitter is a tool for generating a C# REST API client using the Refit library. Prior to 2.1.2, OpenAPI `paths`-object keys are emitted verbatim into Refit route attributes such as `[Get("<path>")]` without escaping quotation marks or restricting characters. An attacker-influenced single-line, slash-prefixed path survives default validation without `--skip-validation` and can close the attribute string, interface, and namespace while introducing a top-level file class and reopening the generated structure to keep valid C#. A `[ModuleInitializer]` method executes attacker code when an application compiles and loads the generated assembly at startup, even without calling the generated client. The enum and default value sinks are escaped and are not the vulnerable path-emission sink. The behavior was verified on Refitter 2.0.0 with .NET 8. This issue is fixed in version 2.1.2. |
Risk And Classification
Primary CVSS: v4.0 8.6 HIGH from [email protected]
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
EPSS: 0.003500000 probability, percentile 0.287080000 (date 2026-10-31)
Problem Types: CWE-94 | CWE-1116 | CWE-94 CWE-94: Improper Control of Generation of Code ('Code Injection') | CWE-1116 CWE-1116: Inaccurate Comments
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 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/C... |
| 4.0 | CNA | DECLARED | 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 |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
NonePrivileges Required
NoneUser Interaction
ActiveConfidentiality
HighIntegrity
HighAvailability
HighSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS: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
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Christianhelle | Refitter | affected < 2.1.2 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/user-attachments/files/29395229/make_spec.py | [email protected] | github.com | |
| github.com/user-attachments/files/29395228/maintainer-report.txt | [email protected] | github.com | |
| github.com/user-attachments/files/29395230/reproduce.sh | [email protected] | github.com | |
| github.com/christianhelle/refitter/security/advisories/GHSA-3fhm-p725-h3g3 | [email protected] | github.com | |
| github.com/christianhelle/refitter/pull/1178 | [email protected] | github.com | |
| github.com/christianhelle/refitter/releases/tag/2.1.2 | [email protected] | github.com | |
| github.com/christianhelle/refitter/commit/793d2632899c2022511dfc15e30725... | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.