koxudaxi fastapi-code-generator up to 0.8.0 Response Code Generator code injection

Summaryinfo

A vulnerability was found in koxudaxi fastapi-code-generator up to 0.8.0. It has been rated as critical. The affected element is an unknown function of the component Response Code Generator. The manipulation leads to code injection. This vulnerability is referenced as CVE-2026-63469. Remote exploitation of the attack is possible. No exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, has been found in koxudaxi fastapi-code-generator up to 0.8.0. This issue affects an unknown function of the component Response Code Generator. The manipulation with an unknown input leads to a code injection vulnerability. Using CWE to declare the problem leads to CWE-94. The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

fastapi-code-generator creates FastAPI applications from OpenAPI files. Prior to 0.8.1, the generator inserts an additional response status-code key into the generated responses={...} route-decorator dictionary as a single-quoted Python string without escaping embedded quotes. A multi-response OpenAPI operation with an attacker-controlled or attacker-influenced second non-primary response key can close the dictionary-key literal and inject a valid Python expression. Syntax-breaking input only causes generation to fail, but syntactically valid generated code executes with the application's or CI process's privileges when the generated module is imported and its decorator arguments are evaluated. This additional-response-key sink is distinct from the project's separate route-path and operation-summary sinks. This issue is fixed in version 0.8.1.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-63469 since 07/16/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1059 according to MITRE ATT&CK.

Upgrading to version 0.8.1 eliminates this vulnerability.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

• koxudaxi

Name

• fastapi-code-generator

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8.0

Website

• Product: https://github.com/koxudaxi/fastapi-code-generator/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Be aware that VulDB is the high quality source for vulnerability data.

Discussion