CVE-2026-63345
Published:October 30, 2026
Updated:November 04, 2026
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 Packages
Refitter.Core (DOT_NET):
Affected version(s) >=0.2.1.0 <2.1.2 || >=1.0.0.0 <2.1.2 || >=2.0.0.0 <2.1.2Fix Suggestion:
Update to version 2.1.2https://github.com/christianhelle/refitter.git (GITHUB):
Affected version(s) >=0.1.3-alpha <2.1.2 || >=1.0.0 <2.1.2 || >=2.0.0 <2.1.2Fix Suggestion:
Update to version 2.1.2refitter.core (NUGET):
Affected version(s) >=0.2.1-alpha <2.1.2 || >=1.0.0 <2.1.2 || >=2.0.0 <2.1.2Fix Suggestion:
Update to version 2.1.2refitter (NUGET):
Affected version(s) >=0.1.2-alpha <2.1.2 || >=1.0.0 <2.1.2 || >=2.0.0 <2.1.2Fix Suggestion:
Update to version 2.1.2Related Resources (9)
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Contact UsCVSS v4
Base Score:
8.6
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
ACTIVE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
8.8
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
EPSS
Base Score:
0.35