CVE-2026-63344：Refitter 內容型別鍵注入漏洞 影響 C# REST API 客戶端生成
CVE-2026-63344 - Refitter: C# source injection through OpenAPI content-type map keys
Refitter 在 2.0.0 版本中，OpenAPI 描述的內容型別鍵未經轉義，導致生成的 C# 程式碼中可注入任意內容，並在載入時執行攻擊者程式碼。
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.
Impact
Affected Products
The following products are affected by CVE-2026-63344
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
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are
affected, the information is not represented in the table below.
No affected product recoded yet
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | HIGH | [email protected] |
Update Refitter to version 2.1.2 or later to fix content-type header injection.
- Update Refitter to version 2.1.2 or later.
- Review generated API clients for malicious code.
- Validate OpenAPI descriptions for correct content-type keys.
Here, you will find a curated list of external links that provide in-depth
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CVE-2026-63344.
While CVE identifies
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weaknesses that can lead to vulnerabilities. CVE-2026-63344 is
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weaknesses.
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The following table lists the changes that have been made to the
CVE-2026-63344 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
十月. 30, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V4.0 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 Added CWE CWE-94 Added CWE CWE-116 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/63xxx/CVE-2026-63344.json">CVE-2026-63344</a> Added Reference https://github.com/christianhelle/refitter/commit/ab4d8e439d6f0ee82ad49ee15323978d70fe5a67 Added Reference https://github.com/christianhelle/refitter/pull/1178 Added Reference https://github.com/christianhelle/refitter/releases/tag/2.1.2 Added Reference https://github.com/christianhelle/refitter/security/advisories/GHSA-p32v-8v8j-j534 Added Reference https://github.com/user-attachments/files/29394848/reproduce.sh Added Reference https://github.com/user-attachments/files/29394851/maintainer-report.txt Added Reference https://github.com/user-attachments/files/29394853/make_spec.py
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.