CVE-2026-63471

CRITICAL
INFO Priority: 0.03 BB Relevance: 79/100
Published: 2026-11-03 Modified: 2026-11-07 First seen: 2026-11-03 Status: active

Attack Surface

Network Low Complexity No Auth No Interaction Conf. Impact Integ. Impact

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: None
S: X
AT: None
VC: High
VI: High
VA: High

Description

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.

Affected Software (2)

VendorProductVersion
koxudaxi fastapi-code-generator < 0.8.1
koxudaxi fastapi-code-generator < 0.8.1

Bug Bounty Relevance

79 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

9.3 / 10.0 v4.0
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/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

EPSS — Exploitation Probability

0.31%
Raw Score 0.003120
Percentile 24.5%
Date 2026-11-14

EPSS Trend

2026-11-14
0.00312
2026-11-13
0.00312
2026-11-12
0.00312
2026-11-10
0.00312
2026-11-09
0.00312
2026-11-08
0.00312
2026-11-07
0.00312
2026-11-06
0.00312
2026-11-05
0.00312
2026-11-04
0.00312

Intelligence Sources

mitre ref →
nvd ref →