CVE-2026-63345

Full vulnerability record from the local CVENow database.

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.

Severity

HIGH

CVSS score

8.6 (v4.0)

Vulnerability status

Received

Source identifier

[email protected]

Published

2026-10-30 23:17:13.987000

Last modified

2026-10-30 23:17:13.987000

View original CVE JSON

{
  "id": "CVE-2026-63345",
  "sourceIdentifier": "[email protected]",
  "published": "2026-10-30T23:17:13.987",
  "lastModified": "2026-10-30T23:17:13.987",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "christianhelle",
          "product": "refitter",
          "versions": [
            {
              "version": "< 2.1.2",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "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",
          "baseScore": 8.6,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "privilegesRequired": "NONE",
          "userInteraction": "ACTIVE",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnAvailabilityImpact": "HIGH",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "subAvailabilityImpact": "NONE",
          "exploitMaturity": "NOT_DEFINED",
          "confidentialityRequirement": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "valueDensity": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-94"
        },
        {
          "lang": "en",
          "value": "CWE-1116"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/christianhelle/refitter/commit/793d2632899c2022511dfc15e30725ef69073973",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/christianhelle/refitter/pull/1178",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/christianhelle/refitter/releases/tag/2.1.2",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/christianhelle/refitter/security/advisories/GHSA-3fhm-p725-h3g3",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/user-attachments/files/29395228/maintainer-report.txt",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/user-attachments/files/29395229/make_spec.py",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/user-attachments/files/29395230/reproduce.sh",
      "source": "[email protected]"
    }
  ]
}