CVE-2026-63471

9.3 CRITICAL 0.3% exploit odds Fix listed Injection Web app

What it is

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.

At a glance

Exploitability: Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.
Exploit odds: 0.3% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-07-16 21:37 UTC ReservedThe CVE id was reserved by its CNA
2026-11-03 20:18 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-11-07 04:17 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.3% in the next 30 days (EPSS).
Severity: 9.3 CRITICAL (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-11-03 20:18 UTC
Last modified: 2026-11-07 04:17 UTC
Exploit probability: 0.3% · EPSS, next 30 days
Weakness: CWE-94 · Code injection
Record status: Deferred

Attack profile CVSS 4.0 · 9.3

Attack vector: Network
Complexity: Low
Attack requirements: None
Privileges needed: None
User interaction: None
Confidentiality: High
Integrity: High
Availability: High

Raw vector

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

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-63471.md and follow it. Check whether this project is affected by CVE-2026-63471. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record