fastapi-code-generator creates FastAPI applications from OpenAPI files.
CVE-2026-63471
fastapi-code-generator creates FastAPI applications from OpenAPI files. Prior to 0.8.1, the generator inserts an OpenAPI path into a generated @app.get(...) route decorator as a single-quoted generated route string without escaping embedded quotes. An attacker-controlled or attacker-influenced OpenAPI path can close the string and inject a valid Python expression into the decorator argument. 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 the decorator is evaluated. This OpenAPI path sink is distinct from the project's separate operation-summary docstring and additional-response-key sinks. This issue is fixed in version 0.8.1.
Assessment
- CVSS
- 9.3 (v4.0)
- Severity
- Critical
- Known exploited
- Not listed in CISA KEV
- Exploit availability
- Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
- Published
- 3 November 2026
- Last updated
- 3 November 2026
- Affected
- koxudaxi · fastapi-code-generator
- Assigner
- GitHub_M
CVSS vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
At the source
References
- https://github.com/koxudaxi/fastapi-code-generator/security/advisories/GHSA-p2mm-64f6-gmpp
- https://github.com/koxudaxi/fastapi-code-generator/commit/49301dbdb82170d7f50877419d994b05cb1fa2bc
- https://github.com/koxudaxi/fastapi-code-generator/commit/b3b9bd66e0b0c4d8c686fda700258104615a1332
- https://github.com/koxudaxi/fastapi-code-generator/releases/tag/0.8.1
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