{"id":"CVE-2026-63470","title":"fastapi-code-generator: Call-time RCE via operation summary -> unescaped route-handler docstring","summary":"fastapi-code-generator creates FastAPI applications from OpenAPI files. Prior to 0.8.1, the generator inserts Operation.summary into a generated route-handler docstring as a triple-double-quoted string without escaping embedded triple qu…","severity":"critical","cvss":9.3,"cvssVector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","cvssSource":"cna","cwe":["CWE-94","CWE-116"],"vendor":"koxudaxi","product":"fastapi-code-generator","affected":["fastapi-code-generator < 0.8.1"],"ssvc":{"exploitation":"poc","automatable":"yes","technicalImpact":"total","timestamp":"2026-11-03T19:34:23.694611Z"},"exploitAvailable":true,"published":"2026-11-03","updated":"2026-11-03","sourceUpdated":"2026-11-03T19:34:47.499Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-63470","references":[{"url":"https://github.com/koxudaxi/fastapi-code-generator/security/advisories/GHSA-h667-4jj2-cgv4","label":"https://github.com/koxudaxi/fastapi-code-generator/security/advisories/GHSA-h667-4jj2-cgv4"},{"url":"https://github.com/koxudaxi/fastapi-code-generator/commit/49301dbdb82170d7f50877419d994b05cb1fa2bc","label":"https://github.com/koxudaxi/fastapi-code-generator/commit/49301dbdb82170d7f50877419d994b05cb1fa2bc"},{"url":"https://github.com/koxudaxi/fastapi-code-generator/commit/b3b9bd66e0b0c4d8c686fda700258104615a1332","label":"https://github.com/koxudaxi/fastapi-code-generator/commit/b3b9bd66e0b0c4d8c686fda700258104615a1332"},{"url":"https://github.com/koxudaxi/fastapi-code-generator/releases/tag/0.8.1","label":"https://github.com/koxudaxi/fastapi-code-generator/releases/tag/0.8.1"}],"tags":["cve.org","exploit-available"],"epss":0.00468,"epssPercentile":0.40603,"ingestedAt":"2026-11-05T20:33:06.397Z","slug":"CVE-2026-63470","body":"## Overview\n\nfastapi-code-generator creates FastAPI applications from OpenAPI files. Prior to 0.8.1, the generator inserts Operation.summary into a generated route-handler docstring as a triple-double-quoted string without escaping embedded triple quotes. An attacker-controlled or attacker-influenced operation summary can close the docstring and inject a valid Python expression statement into the handler body. Syntax-breaking input only causes generation to fail, but syntactically valid generated code executes with the server process's privileges when the affected route handler is called. This call-time route-handler docstring sink is distinct from the project's separate import-time route-path and additional-response-key sinks. This issue is fixed in version 0.8.1.\n\n## Affected\n\n- `fastapi-code-generator < 0.8.1`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"abyssal","depthScore":63,"depthScoreParts":{"impact":51.2,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[]}